A brutal regime hid hundreds of people’s remains. Can new forensic science help find them — and regain public trust?

In August of 2023, as the 50th anniversary of Augusto Pinochet’s bloody 1973 coup d’état drew near, President Gabriel Boric of Chile stood before the presidential palace in downtown Santiago and spoke about memory. “During these days in which there are people who dare to deny all of this,” he said in Spanish, referring to the country’s rising denialism of Pinochet’s spate of crimes, “how do you respond to those people who invite us to forget?”

The question wasn’t merely rhetorical. Beneath a wide canopy blocking the midday sun, a few hundred people — relatives of Pinochet’s victims, journalists, a coterie of government officials — had gathered to hear Boric unveil his administration’s response: The Plan Nacional de Búsqueda, or National Search Plan, a highly anticipated initiative harnessing new technologies and scientific techniques to uncover the remains of Chileans abducted and likely killed as part of Pinochet’s infamous, post-coup crackdown. More than 1,000 victims of such enforced disappearance have never been found. Of those who disappeared, Boric said, “we want to recover their stories to be able to reconstruct our own, because when we forget, we also lose a fragment of ourselves, of what we can be.”

“My memory,” he added, “is incomplete because I am missing the disappeared.”

The oratory was effective — tears flowed freely, and the occasional cry of “Que Viva Presidente Boric!” issued from the crowd. But for Flor Lazo, the president of the Association of Relatives of the Detained, Disappeared, and Executed of Paine, memory had never been a problem. Her father, two brothers, and two uncles had been among the 70 people who were forcibly disappeared from Paine, a small agricultural area 30 miles south of Santiago, in the weeks following the coup — the worst per-capita case of repression of the entire dictatorship. For decades, Lazo, like so many others, had searched for her loved ones. For her efforts, she had suffered maltreatment, indifference, and humiliating scientific blunders by the state, the last occurring after Pinochet’s reign had ended. As she sat in the front row listening, the betrayals cast a shadow over Boric’s lofty rhetoric. “Trust,” she had explained a few weeks prior, “is something that is very delicate.”

Although Boric’s National Search Plan is the largest and most ambitious official effort to date, it is not the first. With the country’s return to democracy in 1990, scientists and medical professionals, both independent and state-affiliated, began investigating the mass graves that appeared in the dictatorship’s wake. The investigations often employed the techniques and methodologies of a scientific discipline — forensic anthropology — that was new in Chile, taught by foreign scientists as the most effective method of investigating mass atrocity.

Many of Chile’s earliest forensic anthropology researchers entered the discipline because of their own personal experiences with Pinochet’s violence — some had themselves been imprisoned, tortured, or forced into exile, while others had lost loved ones. They viewed the work, much like Boric does today, as an obligation to the dead, and as a repudiation of Pinochet’s attempts at historical erasure. But in the cauldron of vying political and social pressures in post-dictatorship Chile, the idealism and conviction of the newly trained forensic anthropologists and archeologists often clashed with the state’s own forensic unit, the Servicio Médico Legal, or SML, ultimately culminating in disaster. A series of scientific errors in the 1990s led to mistaken identifications for many of the bodies, sparking an investigation that would reveal ineptitude, unprofessionalism, and a string of ethically questionable decisions. For many of the affected relatives, the impact was seismic, forever altering their relationship to science, the state, and the notion of truth itself.

“A long, long, long, long road in search of the truth.”

Now, as the state once again embarks on a concerted effort to find the victims, the ghosts of its past have reawakened. The SML, which by Chilean law must play a central role in the new forensic effort, is now widely despised and distrusted. At a meeting for the National Search Plan in July of 2023, one government official sarcastically remarked that SML representatives could not attend “because they would have vegetables thrown at them.” But despite her doubts, Lazo has chosen to throw her support behind the plan. Keenly aware of an ascendant right that could take power this year, Lazo views the plan as perhaps the last opportunity for many of her generation — the last living generation to have experienced the post-coup violence directly — to gain closure. At the same meeting where SML officials were unwelcome, Lazo had addressed the group: “We’re in a tremendously critical moment politically,” she said. “We have to assume also that maybe in two more years, we won’t be able to talk about this. But we have to keep fighting.”

For Lazo, it has been a lifetime of fighting. Several weeks after Boric’s announcement, she sat in the dining room of her home in Buin, near Paine, her arms folded across a dark oak table — the same table, she explained, over which her family had enjoyed their final meal together all those years ago. She was 15 years old the night her father and brothers were taken. Now she is 66. Speaking softly, her eyes smoldering, she leaned forward and began to describe those 50 years: armed men with faces painted black, anguished crowds, a skeleton on an aluminum tray, a shattered grave. “A long, long, long, long road,” she said, “in search of the truth.”

Before Pinochet’s takeover, the Lazo family lived a quiet and content life in Paine. Flor Lazo’s father, Samuel, and older brothers, Samuel del Transito and Rodolfo, were farmers with the Nuevo Sendero agricultural syndicate, which had received land as part of recent reforms. And although tensions had begun to simmer between the region’s farmers and its previous private landowners, life, for the most part, was peaceful. “Even with all of the limitations with farm life,” said Lazo, “we were happy.”

The year preceding the coup was especially joyous. Rodolfo and a neighbor girl named Alejandrina had fallen in love, and were soon married in a large church in Paine. After the ceremony, the Lazos hosted a blowout party at their house, with some 60 guests singing and dancing cumbia to vinyl records. And there was another thing to celebrate too: Alejandrina could not hide the bulge of her belly, which protruded visibly beneath her wedding gown.

Despite the merriment, however, Lazo’s cousin, Juana, remembers the wedding party with a tinge of sadness. It’s her only memory of the extended family all together. “A while after that,” she said, “our family started disappearing.”

Just days after the coup, a brutal wave of repression engulfed Paine; civilians were beaten, abducted, and worse. By mid-October, dozens of men, most of them affiliated with the agricultural syndicates, had been taken from the various settlements of the area. Some were released. A few turned up dead — among them, Lazo’s uncle, Raúl, whose mutilated body was discovered in the nearby Collipeumo River. Many more, however, simply vanished.

Flor Lazo sits at the family dining table in November 2023, at her home in Buin, Chile. This table, one of the few remaining objects from her childhood, was where the Lazo family shared all their meals growing up. After the 1973 coup, Pinochet’s regime targeted her family. Her father and brothers were detained and disappeared during the crackdown that followed.

Family photographs and portraits of Flor Lazo’s disappeared father and brothers, who were farmers with the Nuevo Sendero agricultural syndicate, are displayed in her home. In the center is a portrait of her father and mother.

A few hours before sunrise on Oct. 16, 1973, Flor Lazo recalls, her family awoke to the sound of rifle butts smashing against their wooden door. Men wearing military fatigues, their faces painted black, entered the house and dragged Flor’s father and brothers out to the street, where a truck idled in the darkness. Rodolfo’s face was white with fear as he left Alejandrina and their newborn baby, Beatriz, behind, Lazo recalled. She tried to follow them out the door, but her father, from somewhere out in the darkness, asked her to go back inside.

The next day Lazo, her mother, and family members of another 19 men taken the same night began to search. They inquired at the nearby San Bernardo School of Infantry but were turned away. Then, they began making daily trips to Santiago, figuring the men could be incarcerated at the National Stadium, the capital’s colossal sports complex, which the regime had converted into a prison camp. The scenes there often turned chaotic, as guards repelled crowds of similarly anguished relatives, sometimes resorting to beatings. Each night, Lazo and the older women would return to Paine empty-handed, exhausted, and heartbroken.

The search continued for weeks, then months, then years. Despite their perseverance, however, it was fruitless. “Nothing, nothing, nothing,” said Lazo. “It was as if the earth had just swallowed them whole.”

When the regime did mention the disappeared, it was to try to erase them from history. “Many of the presumed dead have no legal existence,” one official reportedly told the United Nations in 1975. Victims such as Lazo’s relatives, the regime seemed to suggest, were mere phantoms of their imaginations. For years, through the courts, the government ministries, and the secret police, Pinochet maintained a culture of denial and secrecy.

But if the dictator and his functionaries refused to speak, their victims — even from beyond the veil of death — refused to remain silent.

Families of the disappeared from Paine listen to speeches during a commemorative event on Sept. 10, 2023, at the Paine Memorial in Paine, Chile. The memorial honors the men who were abducted, unlawfully arrested, and killed under Pinochet’s dictatorship.

The first of the Pinochet regime’s mass graves was discovered on Nov. 30, 1978, when an elderly man came across 15 skeletons hidden in an abandoned lime kiln some 12 miles northwest of Paine. The following year, a second mass burial site, holding 19 sets of remains, was found in a cemetery in Yumbel, a city some 300 miles south of the capital. Meaningful investigations of such sites were thwarted by Pinochet’s military courts, however, while other mass graves were clandestinely exhumed by the regime, which incinerated the remains or threw them from helicopters into the sea or elsewhere. Still, the bodies provided a stark corrective to the regime’s denials.

Forensic anthropology did not yet exist as a discipline in Chile, however, and many of those who would later pioneer it were still students in the 1970s and early 80s. Several were themselves victims of the types of abuses they would later investigate. Iván Cáceres, for instance, before studying archaeology at the University of Chile, witnessed his mother and countless friends arrested by the regime, and he himself went into hiding. “I had an environment that was very hard hit by the dictatorship,” he said. Similarly, Isabel Reveco, an anthropology student at the University of Chile, came from a politically active, anti-Pinochet family. By 1981, she and three of her six siblings had been detained by the regime, and many had been tortured. A family friend was abducted on Oct. 17, 1977, and never returned. “I became a forensic anthropologist to look for her,” said Reveco. “Just for that.”

The search continued for weeks, then months, then years. Despite their perseverance, however, it was fruitless.

In neighboring Argentina, in the mid-1980s, a forensic anthropologist from the United States named Clyde Snow had begun to adapt the field, which previously had consisted mostly of lab-based bone analysis, to cases of human rights abuses and mass atrocity. “He realized that he needed to be at the gravesite,” said Dennis Dirkmaat, chair of the Department of Applied Forensic Sciences at Mercyhurst University in Pennsylvania. “He was trained in archaeology, and so he would be one of the first, certainly in this human rights environment, to talk with the families and go to the gravesite.” In 1984, Snow trained a team of young Argentine graduate students to investigate the crimes of the military dictatorship in that country, which had ended in 1983. And in the late 1980s, at the request of the relatives of the missing, Snow began training people as part of a similar effort in Chile. Cáceres and Reveco, as well as several others, soon joined.

The Group of Forensic Anthropologists, or GAF, began with a period of specialized training under Snow. The method he taught was an amalgamation of archaeology, physical anthropology, odontology, anatomy, osteology, and more. Among Snow’s innovations, said Dirkmaat, was an emphasis on interpreting signs of trauma in skeletons, as well as analyzing the setting and context in which bones are found. “He’s like 30 years ahead,” said Luis Cabo-Perez, a forensic anthropologist at Mercyhurst who works closely with Dirkmaat. “He had all these modern conceptions of forensic anthropology.”

The aim of the work, of course, was to uncover the identities and circumstances of death of victims of mass atrocity. To do that, forensic anthropologists developed two sets of reports. The first, called the antemortem report, contained information about the life of a potential victim — medical and dental records, interviews with family members, photographs. The second, called a postmortem report, involved detailed analysis of skeletal remains — determining height, approximate age, sex, signs of trauma, markers of disease. Then, the two sets of reports were compared, looking for points of overlap.

A gold filling in the tooth of a skeleton, for example, could match a dental record. A long-healed femur fracture could dovetail with reports that the victim had once broken their leg in a motorcycle crash. Osteoporosis could indicate alcoholism, stained teeth could point to a smoker. It was the forensic anthropologist’s job to search for multiple points of concurrence. “All that data is in the bones,” said Cáceres.

The ocean near Antofagasta, Chile, photographed in 2023. During Pinochet’s regime, the Pacific Ocean was used as a site for disposing of bodies, reflecting the regime’s efforts to hide the evidence of its brutal repression.

But in adapting the field to cases of mass killing, unforeseen challenges also emerged. For example, state violence would often target people within similar demographic groups. “In Chile or Argentina, like the desaparecidos, you have a lot of, for example, students, college students and so on, so very similar physical or biological profiles,” said Cabo-Perez, which made it more difficult to tease out specific identities.

Additionally, whereas forensic anthropologists in other contexts collaborated closely with law enforcement to obtain information about victims, that was impossible in Argentina and Chile — the police were often themselves responsible for the disappearances. This forced the forensic anthropology teams to instead work closely with the families of the missing, which, according to Dirkmaat and Cabo-Perez, could introduce the possibility of bias. “If you talk with a couple of parents who are like, they don’t know what happened to their kid or their daughter and they are in very bad shape and have come to you, the next set of remains you examine in the lab, you’re going to want them to be that person that they’re missing,” said Cabo-Perez. “It’s almost unavoidable.” Dirkmaat agreed, adding that “those are the worst errors that we could make in this scientific discipline.” But in Chile in the late 1980s, concerns over bias were perhaps less well-understood than they are now. According to Reveco, close working relationships with the families were central to the method: “We were at their service,” she said.

While the GAF was training in the techniques of forensic anthropology, an unprecedented groundswell of hope had swept Chile: The end of Pinochet’s reign was in sight. In Paine, Lazo and her family greeted the news of the dictator’s defeat in a 1988 presidential referendum with jubilation and hope. “I got up from my bed, I remember, and I hugged my mom,” she said. “And I hugged my sister. And I told her, crying, I said that we were going to know about our family, because in democracy, we were going to know the truth. And we were going to have justice.”

Justice would prove to be elusive. Still, when Pinochet finally stepped down from the presidency on March 11, 1990, human rights groups perceived an opportunity to launch serious, unfettered investigations into the regime’s crimes. And all eyes fell on one site in particular: a small section of Santiago’s General Cemetery, called Patio 29, which for years had been rumored to contain hundreds of victims.

The cemetery is vast and quiet, walled off from the clamor of Santiago’s bustling streets. Towering trees line the wide avenues between tombs, and everywhere regal mausoleums rise to honor Chile’s luminaries. But further back, the tombs become gradually less ornate, giving way to a series of open, grassy plots marked with jagged iron crosses. Santiago’s forgotten are buried there — the impoverished, the unknown, and unclaimed. And it was there, in an area designated Patio 29, that Pinochet’s regime disposed of many of its victims.

In 1991, a judge in Santiago named Andrés Contreras, responding to a complaint filed by a human rights group, ordered the excavation of Patio 29. He chose Reveco and Cáceres of the GAF to lead the dig. It was an enormous responsibility for the still-green GAF, and the attention of the entire country turned toward them as they began to work.

Patio 29, the site of a mass grave at the Santiago General Cemetery where Pinochet’s regime disposed of bodies, shown in October 2023. Forensic misidentifications, including those of Flor Lazo’s brother, Rodolfo, originated from this site.

During the first two weeks of September, the team exhumed 106 graves, which contained 125 sets of human remains. (A few years later one more skeleton was exhumed.) The caskets, some of which contained multiple bodies, had collapsed, requiring the scientists to carefully remove the dirt and shards of wood surrounding the bones. Bullets, left behind after soft-tissue had decomposed, lay strewn among the skeletons. “It was a very hard job, very sad to do,” Cáceres said, “because we were taking from the past and bringing to the present all this horror that occurred.”

After the exhumations, the remains were transferred to the SML morgue, and the long process of identification began. Both the GAF and the SML carried out analyses of the skeletons, the teams working separately but in parallel at the SML’s headquarters. From the outset, the work encountered obstacles — the antemortem reports often contained unhelpful information and the skeletons, mostly from men between ages 25 and 40, were difficult to distinguish. A series of professional rivalries and grudges also complicated matters.

Reveco, Cáceres, and the other members of the GAF shared a widespread distrust of the SML, who many viewed as complicit in covering up crimes from the dictatorship. And although a new director had been appointed, many of the Pinochet-era personnel remained, leading to a rancorous atmosphere. Increasingly, too, there were tensions within the GAF. As the skeletal analysis dragged on for months and then years, members of the organization left to pursue other endeavors. Fewer human-rights cases were appearing, and funding was running thin. Cáceres felt the group should venture into historical and non-human-rights-related criminal cases, but Reveco opposed this. They began to clash over the future of the organization.

As tensions came to a head within the GAF, Reveco made the decision to leave the organization. Shortly after, she received a surprising offer: A forensic doctor at the SML, Patricia Hernández, was forming a new identification unit, and she wanted Reveco to join. At first, Reveco recalled, the idea seemed ridiculous. It felt like going into the SML “was like treason,” she said. Still, many families of the disappeared implored her to join, so that they would have someone they could trust within the SML. Reveco ultimately agreed, causing a rift with Cáceres, who saw the move as a disappointment.

Upon Reveco’s arrival in 1994, the SML accelerated the pace of identifications of the Patio 29 bodies, work that had previously been undertaken by both the GAF and SML teams. (The GAF ceased recommending IDs to the judge in late 1993.) With each possible match, the SML team informed Judge Contreras, who was responsible for rendering a final judgement on the match and ordering delivery of the remains to relatives. In this manner, during the mid and late 1990s, dozens of bodies were identified and delivered to families all over Chile for reburial.

One day near the end of 1994, Flor Lazo was sitting in her living room watching television when the phone rang. It was Isabel Reveco. She requested that Lazo come to the SML headquarters in Santiago to discuss an important matter. When Lazo arrived, Hernández sat her down and delivered the news she had longed to hear for over 20 years: Her older brother, Rodolfo, had been found.

The skeleton was arranged for her to see in the lobby. Lazo recalled Hernández explaining how Rodolfo had been shot more than two dozen times before being thrown into the San Carlos Canal in eastern Santiago; later, his body was retrieved and hidden away in one of Patio 29’s unnamed graves. “She said it with such tremendous convincing power,” Lazo said. “I believed in science. I believed that it was true.”

A file for Rodolfo, photographed in 2024. Rodolfo was 20 years old when he was detained and disappeared on Oct. 16, 1973, shortly after Pinochet’s regime took power.

Flor Lazo’s cousin, Juana Lazo González, holds a portrait of her cousin Rodolfo in the city center of Paine, in 2024.

At an all-night wake in Paine, in a modest chapel just down the street from where the Lazo men had been abducted, three small wooden caskets were illuminated by tall candles and adorned with roses and laurel wreaths to honor Rodolfo along with two other local men who had been identified at Patio 29. The following morning, a procession drove the caskets to the Paine cemetery for a funeral. There, Lazo recalled, she spoke to her brother. “You returned home,” she said.

That sense of closure, however, was not shared by everyone. Perhaps unwilling to accept the violence that had befallen her son, Lazo’s mother, Teresa, refused to believe that the body in the casket belonged to Rodolfo. At the time, it seemed to Lazo that her mother was simply in denial. But Teresa wasn’t the only one who harbored doubts. In Santiago, months prior, Iván Cáceres had tried to warn the judge who had ordered the excavation: Some of the identifications, he believed, were wrong.

Over the next year, however, scientists cast further doubt on the SML’s work. In November 1994, Hernández traveled to Glasgow, Scotland, in possession of sensitive cargo: 21 plaster casts of skulls from Patio 29, bone samples from 20 of the skeletons, and blood and hair samples from 19 families presumed — based off possible matches already determined by the SML — to be related to those specific sets of remains. Upon her arrival in Glasgow, she handed over the material to Peter Vanezis, then head of the Department of Forensic Medicine and Science at the University of Glasgow. The Chilean government had contracted him to examine the samples using techniques unavailable in Chile at the time, including mitochondrial DNA analysis. This type of DNA analysis looks at genetic material passed through the maternal line, and can be used to conclusively rule out matches, but not to conclusively confirm them.

The results of Vanezis’ DNA analysis revealed widespread discrepancies. “Although we were able to successfully extract mitochondrial DNA from all the skeletal samples and from all of the samples from relatives, without contamination,” Vanezis wrote in a report, “we were unable to find a match between any of the relatives with any of the bone samples.” In a subsequent report, Vanezis mentioned two possibilities that could explain the results: that the DNA had become contaminated, which he said was “unlikely,” or that “the bone samples that have been analyzed are not from the persons to whom they presumably correspond.” By the time he wrote that, the SML had already delivered 91 bodies to supposed relatives back in Chile.

In addition to the DNA analysis, the “Glasgow report,” as it became known, also contained an evaluation of plaster casts of skulls of Patio 29 victims, an effort that was hindered due to the poor quality of the casts. The medley of results — some reliable, some not — created an uproar at the SML. “We saw that there were meetings left, right, and center,” recalled Reveco. “And we saw that they were all angry. I mean, what was happening? We didn’t know anything.” At one point, Reveco said, she was called to a director’s meeting at the SML. “They say: ‘That means that it could all be wrong. And that invalidates all the work we have done. We shouldn’t talk about it. We should remain calm and see what happens next.’”

Reveco’s testimony to a congressional investigation committee in 2006 states that after reading the Glasgow report, she composed a written response to it, which was delivered to the director of the SML. Her testimony also reiterated her opinion of the report: “I believe that it has no scientific validity, and that the conclusions they reached seem to me to be not very serious.”

Marisol Intriago Leiva, who directed the SML unit that oversaw identifications from the mid-2000s until its recent dissolution as part of an institutional restructuring, has a different view of the Glasgow report’s validity. After the SML acquired its own mitochondrial DNA analysis capabilities in the early 2000s, it reexamined all the samples that were sent to Scotland. The results aligned with the Glasgow report. “These are exactly those given by Dr. Vanezis,” said Intriago.

The Glasgow report was never officially submitted to Judge Contreras of the Patio 29 case (although it was informally mentioned to him), nor was it made public. “It was stored away by the director,” said Reveco. “Nothing more was ever said or asked about Glasgow.” Over time, the report became a sort of myth that haunted the corridors of the SML, known by a few to exist but seldom seen.

Meanwhile, the identifications of the Patio 29 victims continued, as did the delivery of bodies.

Flor Lazo, who by the mid-1990s had followed her mother in moving to a town near Paine called Maipo, was unaware of the turmoil at the SML. For her, in fact, the 1990s and early 2000s were a period of tranquility and personal advancement. A scholarship offered to victims of the dictatorship had allowed her to study social work at Arcis University, and she also worked as a dental assistant. She entered therapy to begin to heal the trauma she had borne since childhood. During this time, she also met a kind man and became pregnant. When her son was born in 2002, she didn’t have to reach far for a name — she called him Rodolfo.

Lazo raised her son, worked, and continued the search for the missing. In 2002, a judge initiated legal proceedings against Andrés Magaña, a colonel who had been suspected of involvement in the Paine disappearances. It was a rare moment of optimism for the families of the missing. Meanwhile, Lazo maintained close relationships with her sisters and cousins, as well as with Beatriz, Rodolfo’s daughter, who was by then in her late 20s. Like Lazo, Beatriz had been haunted by the disappearance of her father, and had always yearned for his return. “I have no memories. I don’t know who he was,” she said. “But I always had this feeling he would come home one last time.”

Flor Lazo addresses a crowd of families of the disappeared from Paine, along with Chilean government ministers, at the Paine Memorial in September 2023.

Juana Lazo González’s daughter and grandson at the memorial site in Paine during a ceremony in September 2023.

When the body was identified by the SML, Beatriz was relieved. “We just said ‘How good is it that they found him?’” she said. “Because things were left up in the air. We didn’t know anything.” For her, the gravesite became a place of memory and connection to the past. When she had children of her own, she would often take them there.

For the rest of the family, too, the grave became a sacred place. Lazo visited every Sunday, meticulously cleaning the marble lid of the vault and leaving fresh carnations, roses, and lilies. At least once a month, she would gather there with her sisters to pray: “We would always ask his spirit to accompany us, so that we would have the strength to carry on,” Lazo said. “Because life has been very violent to us. Very violent.”

Soon, though, that violence returned. One afternoon in early 2005, the cemetery administrator summoned Lazo to the grave. Upon arriving, she found that the metal handles of the vault had been ripped from their anchors, its marble lid shattered. Inside, the small wooden casket containing the remains was gone. Police, Lazo was told, had come sometime in the night, broken into the vault, and taken it. “We felt so violated,” she said. For the second time, it seemed, Rodolfo had been forcibly disappeared.

Flor Lazo takes a moment to herself at the Lazo family grave plot, where in the 1990s she laid to rest what she believed were the remains of her brother, Rodolfo, returned to her by the Servicio Médico Legal. The bones were later exhumed without her prior knowledge, and DNA analysis revealed that the remains were not those of her brother.

“Everything was wrong,” said Intriago Leiva, who currently works as head of research and innovation for the Carlos Ybar Institute, the academic area of the SML. “From the handling of the remains in the lab to the state of the lab, from the tests and analyses performed to the value given to the techniques, from how the cases are ordered and documented, the folders were a mess. All of them describe a series of very serious shortcomings. And that report is devastating,” Intriago Leiva said. For a unit that had swirled with controversy nearly since its inception, the Granada findings were the last straw. “People were just fired overnight,” Intriago Leiva said. Patricia Hernández’s identification unit was dissolved. (Reveco, for her part, had already left the SML the prior year.)

Meanwhile, the Patio 29 case was transferred to a new judge, Sergio Muñoz, who called for a review of the identifications. As part of the review, he ordered the exhumations, either full or partial, of most of the 96 bodies from Patio 29 that had been delivered and reburied by the families. A thorough evaluation of the identifications, he determined, would require DNA analysis of the remains.

The Paine families, however, were never informed of the exhumation order. Instead, Lazo and others either received calls from people visiting the cemetery or simply arrived to find their graves ransacked and pillaged. One woman reported finding cemetery workers in the act of burning the coffin that had held her brother. In each case, the families were only later informed that the bodies had been removed for DNA testing.

In April of 2006, the families were called to a meeting in Santiago to hear the results of the new mitochondrial DNA analysis. Of the 96 bodies identified from Patio 29, they were told, 48 were confirmed to be incorrect. (Subsequent analysis has revised that number to 59.) According to an account of the meeting by Juan René Maureira, the grandson of one of the Paine victims, the list of 48 erroneous identifications was read aloud to the assembled families. With each name, anguished groans rose from the crowd. Lazo, seated among the other relatives, listened intently to the list, she recalled, “and there was Rodolfo.”

“Everything was wrong. From the handling of the remains in the lab to the state of the lab, from the tests and analyses performed to the value given to the techniques.”

The body the Lazo family had prayed over for more than a decade was proven to be a complete stranger. The betrayal was gutting. “Rage,” said Lazo, expressing a reaction common among many of the families. “I felt rage. And my sisters also felt rage when I told them the news that it wasn’t him. An enormous, enormous, enormous disillusionment. Once again, we felt trampled upon.”

In Santiago, the scandal caused an uproar. Then-President Michelle Bachelet established a presidential commission to look into the matter. An international panel of experts, which included Clyde Snow, was convened to review the practices of the SML. A congressional commission began to call witnesses. One prominent lawyer felt that by failing to provide the Glasgow report to the judge in the case, personnel at the SML had violated the law. The Patio 29 errors dominated the headlines for weeks, and much of the public opprobrium fell on Reveco and Hernández. Reveco, testifying before the congressional investigative committee, refused to believe the results of the DNA analysis, claiming that it was highly unlikely that her unit could have made more than a small handful of mistakes. Moreover, she expressed outrage at her vilification in the public eye: “They have put a tombstone on us by saying that they are erroneous identifications,” she said.

In 2023, the facade of the Servicio Médico Legal in Santiago is shown graffitied with angry comments from those who feel betrayed by the institution. Of the 96 bodies identified from Patio 29 by SML, 48 were confirmed to be incorrect. (Subsequent analysis has revised that number to 59.)

The congressional investigation ultimately found that the SML had committed grievous mistakes. “In summary, the chain of errors and negligence committed by the Legal Medical Service in the process of identification of the remains found in Patio 29,” the commission wrote, “has not only harmed the victims’ families, who today have a legitimate distrust in relation to the actions of that institution, but has also contributed to sowing a blanket of doubts regarding any report issued by it, seriously affecting the functioning of justice in the country.” The investigation cleared what was then known as the Ministry of Justice, which oversees the SML, and it also, very belatedly, vindicated the actions of Iván Cáceres, who raised the first doubts in 1994. If the concerns of GAF experts had been heeded, the committee wrote, “the consequences that the country knows and regrets today would have been avoided.”

Isabel Reveco no longer denies the misidentifications, although she finds the final tally — 59 bodies — difficult to accept. Sitting at a cafe in Santiago last March, she admitted to cultivating a degree of willful ignorance as a defense against her feelings of guilt. “I don’t want to know,” she said. “I have no idea of the number. If you tell me now, I’ll forget by the afternoon. Because it hurts me a lot.” But as she began to speak about the errors, those defense mechanisms quickly fell away. “I think there must be many explanations,” she said. “Perhaps we weren’t experts. We didn’t have the experience, surely. We didn’t consider many factors. We had erroneous information. We had antiquated methods that were very old, and we didn’t have DNA. I believe it must be several things, not one. What I can tell you is that we had the best intentions.” Despite her intentions, however, the fallout from the mistakes has sparked in Reveco a somber reappraisal of her life’s work. “If I could go back in time I would not have become a forensic anthropologist,” she said. “I realized that what I did was useless. I caused pain, and I was so wrong that my work has no validity.”

Dennis Dirkmaat, the Mercyhurst forensic anthropologist, agreed that many factors — a particular empathy for the families, possibly insufficient training, a small team — collided to produce the tragedy. “There’s a lot of things coming together for what appears to be a perfect storm,” he said, later adding: “It shouldn’t have happened.”

In 2005, while Lazo and the other relatives in Paine were still reeling from the surprise exhumations, something remarkable happened: Andrés Magaña, the army colonel, confessed to being in charge of the killings. He said that in 1973 he had directed the executions of 31 men from Paine. Among the execution sites, he later explained, had been an area about a 100-mile drive southwest of Paine, near a large reservoir called Lake Rapel.

The Lake Rapel region is a vast labyrinth of rolling hills, gullies, and creeks, and it took about two years to locate the precise site of the killings. But one day in 2007, a team of investigators were combing through Los Arrayanes ravine, just east of the lake, when they discovered a bone.

An excavation of the site began. Over the course of two months, investigators found some 3,000 pieces of evidence: bone fragments, bullets and casings, clothing scraps. They found eyeglasses and shoes and a silver ring with an inscription of a woman’s name. The woman, who was subsequently tracked down and questioned, confirmed that the ring had belonged to one of the abducted men from Paine. No intact bodies were found, only skeletal fragments, which were shipped to Austria for DNA analysis.

“I felt rage. And my sisters also felt rage when I told them the news that it wasn’t him. An enormous, enormous, enormous disillusionment. Once again, we felt trampled upon.”

On Oct. 16, 2007, after 34 years to the day of searching, the relatives were permitted to visit the execution site. According to Lazo’s cousin Juana, they gathered on a sloping hillside nearby so they could walk as one toward the ravine, raising white handkerchiefs to honor the missing. As they moved forward, they erupted into song — “Un Beso y Una Flor,” a popular Spanish tune about leaving loved ones behind. Then, at the edge of the ravine, they held a mass in remembrance of the missing. “There with my sisters and my mom, we hugged each other,” said Lazo. “And we accepted that cruel reality.”

The DNA analysis of the bone fragments yielded 11 positive matches, confirming that the ravine was the site of the Oct. 16 killings. Among the matches were Lazo’s brother, Samuel del Transito, and her uncle, Carlos Enrique Lazo Quinteros. Bone fragments from two men who had been erroneously identified from Patio 29 were also found, although there was nothing from Rodolfo. Testimony from the killers, however, suggested that he was there too, alongside the 23 other men who were shot that day. (Only bone fragments remained because, according to Magaña, the dead men were disinterred in 1978 as part of a Pinochet-ordered cover-up.)

In the end, the investigation determined that the Lazo men had never been held in the National Stadium, or any of the countless other detention centers where Flor Lazo and the other women from Paine had searched. Nor had they ever been buried in Patio 29. Just hours after they were taken from their homes, the men were driven to the ravine. There, they were pushed to the bottom, arranged in a line, and executed. From the very beginning, Lazo and the others had been searching for ghosts.

Pages in a photo album created by Flor Lazo depict families from Paine receiving the remains of their loved ones after the discovery of the execution site near Lake Rapel. In 2007, bone fragments, bullets and casings, clothing scraps, and personal items were excavated from a ravine in the area. DNA analysis revealed 11 positive matches, including Lazo’s brother and uncle.

President Boric’s new National Search Plan is headquartered at the offices of Chile’s Human Rights Program, on the third floor of an office building overlooking Santiago’s Plaza de Constitución, where he made his announcement for the program in August of 2023. The space is filled with small, glass-walled cubicles where some dozen lawyers, scientists, and researchers, under the leadership of Paulina Zamorano, head of the Human Rights Program, are working to advance the investigations. So far, the work has been slow. “Still no results,” said Juan Mena, then-coordinator of the Plan, in an interview in March 2024, some seven months after its launch. “I know that the result has to be found, but we were making progress, and the team is getting stronger.”

Of Chile’s 1,469 officially-recognized cases of forced disappearance, only 306 victims have ever been found. With the positive identification of at least some of her family members, Lazo joined the relatively small group of relatives who have been afforded some modicum of closure. For thousands more, however, the disappearances remain an inscrutable void, as incomprehensible and harrowing now as they were some 50 years ago. This prolonged uncertainty, the dueling hope and despair, has been described by scholars as a form of psychological torture. It is that anguish the National Search Plan seeks to alleviate.

One of the first major steps the National Search Plan has taken towards that goal has been the commissioning of a new software platform that will help investigators extract information from Chile’s vast library of documents. Unholster, the Chilean software and data science company selected for the project, has finished building the platform, which has digitized and indexed the documents — court records, testimonies, institutional paperwork — and arranged them to help show the relationships between people, organizations, places, and dates connected to the disappearances. This, the team hopes, will help investigators discern the trajectories of each victim, from the moment of their abduction to the location of their final resting place. Sebastian Acuña, Unholster’s chief technology officer, said the company has incorporated artificial intelligence models into the platform, which will speed up the investigations. “I don’t think anything anywhere close to this has existed in Chile before,” he said.

This prolonged uncertainty, the dueling hope and despair, has been described by scholars as a form of psychological torture.

Once new sites of interest are determined — there are already about 50 — the National Search Plan team will turn to remote sensing technologies to home in on potential graves. To scan the terrain, researchers will use aerial photography, satellite imagery, Light Detection and Ranging (or LiDAR, where lasers mounted on airplanes or drones produce high-resolution topical scans of the ground below), and Ground Penetrating Radar, which uses electromagnetic waves to peer into the ground itself. Any disruptions in the earth could signal clandestine burial sites. However, according to Constanza Gnecco, a forensic archaeologist on the National Search Plan team, these technologies have so far only been useful to exclude potential sites. “It has helped to discard areas,” she said. “I haven’t had a single positive result. Never.”

The enormous difficulty of finding gravesites in such a vast and varied landscape has led Gnecco to take great care when discussing the possibilities and limitations of these technologies with families. The Patio 29 errors “ruptured the trust” for a lot of families, she said. To regain that trust, she strives to maintain total transparency in her work, while also explaining to families that disappointing results shouldn’t necessarily lead to pessimism. “You explain that not finding anything, although it is painful to not find anything, also gives us useful information,” she said, later adding: “They also must know that the search will continue.”

A man’s face is mirrored in the windowpane of a train, capturing the scenic landscape near Paine, Chile.

If the gravesites can even be found, the next step is to help identify the human remains. The work of identifying bodies — which once relied heavily on input from forensic anthropologists — has been revolutionized by DNA analysis. These techniques now play the central role in making identifications, and Chile maintains a thorough database of relatives’ DNA. Dirkmaat has even wondered if his field has a future at all. “With DNA, it could cause the extinction of forensic anthropology,” he said, although he believes certain aspects of the field will remain viable.

Additionally, the National Search Plan is exploring the possibility of analyzing environmental DNA — residual DNA that sheds from organisms and embeds in the environment. The technology, in its current state of development, wouldn’t be able to identify specific people. Rather, it may be useful in locating possible burial sites by helping to confirm that bodies had been buried there.

Despite the new scientific and technological advantages, however, at the very center of the National Search Plan remains the Servicio Médico Legal, whose blighted reputation casts a pall over the administration’s efforts. Still reviled and distrusted by many in Chile, the service nonetheless will be legally bound to head the forensic effort in cases where human remains are discovered. This has given rise to a sometimes uncomfortable dynamic, as officials involved with the National Search Plan try to respond to the concerns of family members while remaining steadfast on the centrality of the SML. “The burden of the past mistakes of the [SML] is very heavy,” said Mena, the previous National Search Plan coordinator.

To make matters worse, a new scandal engulfed the SML in early 2023, when media outlets reported that dozens of boxes containing human remains had been improperly stored and neglected at the University of Chile for nearly two decades. At one point, SML officials were told, the room housing the remains had flooded and become infested with fungus. In 2019, the boxes were finally turned over to the SML, who determined that only a small portion of them actually contained relevant human material. Nevertheless, when the story broke, the SML once again found itself on the defensive. Officials there pointed out that they had not been the ones responsible for the improper storage, but it mattered little. In the ensuing media scrutiny, it surfaced that in addition to the boxes, the SML also had in its possession nearly 300 sets of remains for which identification work had stalled, causing an uproar among the relatives of the missing. “This is part of the policy of impunity that the state has had during all these years,” said the Association of Relatives of the Detained-Disappeared, an organization that represents the families, in a statement posted on social media. “There must be political accountability for this new negligence.”

For officials at the SML, however, the controversy represents a worrisome tendency in Chilean society to funnel latent anger and distrust of the state at large toward the service, positioning it as a sort of whipping-boy for the state’s wider transgressions. Authorization for analyzing the boxes of remains, for example, would have had to come from the judiciary, but it did not. Without that authorization, officials point out, the SML’s hands were tied. “The mistrust talks about the Legal Medical Service, but in general the mistrust that exists is a mistrust of the judicial system on one hand and of the Chilean State that did not take ownership of what it is responsible for,” said Marisol Prado, the SML’s current director. “And we as the Legal Medical Service, as the younger sibling of all of this, have received all of this mistrust.”

In some ways, Prado said, the vitriol towards the SML, which began with the Patio 29 scandal, has even contributed to the very institutional dysfunction that it seeks to redress. Regarding the 300 unidentified human bone fragments, for example, families have demanded that DNA analysis be performed by foreign labs, whose work is often grindingly slow. “I have to send it abroad,” Prado said. “Because of the distrust, they don’t allow me to do the work here.”

In order to break that vicious cycle, the National Search Plan has spent a portion of its budget to facilitate a rapid restructuring of the SML. To streamline authorization of forensic work, for example, the service established a new unit solely dedicated to victims of the dictatorship. Additionally, the SML has worked to decentralize, developing more robust regional outposts to respond to the needs of individual communities. “With every passing day we have been working and righting ourselves to regain the trust of the citizens,” Prado said, adding that she is optimistic about the future.

Attendees participate in a commemorative vigil outside the presidential seat on Sept. 10, 2023, the eve of the 50th anniversary of the 1973 coup led by General Augusto Pinochet. Their slogan is “Nunca Más” – “Never Again”.

Candles line the walls around the presidential palace during a commemorative vigil on Sept. 10, 2023. The phrase “¿Dónde Están?” (“Where Are They?”) is illuminated by the candles, referencing the ongoing 50-year search for the disappeared.

But as much as the SML may be looking toward the future, its past continues to hound it. Last year, Chilean media reported a new misidentification fiasco, this time involving a mass grave in La Serena, some 250 miles north of Santiago. Eighteen bodies were exhumed from the grave in 1998, identified by the SML using the same techniques as with Patio 29, and delivered to relatives for reburial. But recent testimony from an ex-soldier cast doubt on one of the identifications. When the remains were exhumed, DNA analysis showed that the bones were actually from two different people — and neither were related to the purported relatives.

The revelation of the errors initiated a cascade of new investigations. In one case, a pair of foot bones in the custody of the SML were linked by DNA to a man who had buried a complete skeleton of his presumed father back in 1998 — raising the question of whose foot bones were in the grave. In another case, the remains of a woman’s supposed father-in-law were found to be a mixture of four unrelated people. According to Intriago Leiva, exhumations of the La Serena victims are in progress. “You already believe that you had your grief resolved, which you had waited so long for,” one relative told a television crew. “And again, they open that wound.”

Prado admits that the past errors overshadowed the SML for many years. “I think that we’re going to be feeling it forever,” she said. “It’s very difficult for us, as the service, to overcome an error.” But she tries to embrace that dark history as a galvanizing force. “We’re going to be better,” she said. “We’re going to help these families to search for and find their family members’ remains if possible.” And if that’s not possible, she said, then at least they can help figure out what happened to the victims and try to determine who was responsible.

The complicated dynamics surrounding the SML are not the only difficulties facing the National Search Plan. In November 2025, Chileans will head to the polls to elect President Boric’s successor (by law, Chilean presidents cannot serve consecutive terms), and recent polling indicates strong support for rightwing political figures. The two leading candidates, Evelyn Matthei and José Antonio Kast, had both been supporters of Pinochet with deep family ties to the regime, and neither have bothered to distance themselves from those positions. Chile’s ascendant right has led many to question whether Boric’s National Search Plan can survive beyond his administration.

“That is a pretty fair criticism,” said Mena, adding: “The problem that the family members correctly identify is that it’s not guaranteed that it’ll be permanent over time.” The plan’s longevity, Mena explained, largely hinges on how successfully it is implemented. “If it becomes a fiasco, and nothing works, and it’s all a mess, and the money given isn’t used properly, sure they could repeal it, using that as an argument,” he said. “If we manage to put together in this time a serious, responsible public policy with its public funds, then I believe that politically, it becomes very costly, even for extreme right movements, to eliminate it.”

“We’re going to be better. We’re going to help these families to search for and find their family members’ remains if possible.”

Additionally, Mena said, many of the changes occurring through the National Search Plan — the fostering of alliances between various civil-society organizations, for example — are developments that will persist. Similarly, Marisol Prado said that the establishment of the dedicated unit for victims of the dictatorship will ensure that those cases remain a central, immutable part of the institution.

The greatest defense the National Search Plan has, however, is public support, and that support begins with regaining the trust of the families. The technological and scientific advances of the plan, said Mena, will be of limited use if they are viewed with suspicion by those they are intended to help. “Rebuilding trust, that is sometimes the most difficult thing,” he said. “You can actually have the science on your side, but if the people that have to believe in the results of the science process don’t believe you, then you haven’t solved the problem.”

But winning back that trust will be a long process, Mena said, requiring full transparency as well as active participation of the families. “The results will not come in the short term,” he said, adding that “this is a difficult path, without a doubt. But I think it is on the right track.”

In October, as the southern-hemisphere spring is peaking, the rolling hills near Lake Rapel, southwest of Paine, are a blaze of wildflowers. Shepherds drive their herds through the shallow valleys, and an occasional pickup truck kicks up dust from a nearby road, but otherwise the land is open and wild. Nestled within the hills, Los Arrayanes ravine, with its steep walls and shadowy tangle of vegetation, would be indistinguishable from countless others were it not for the crosses. They stand on the ravine’s precipice — wood and metal crosses of various colors and sizes — in honor of the 24 men who were executed at sunrise on Oct. 16, 1973. One cross, tall and white, bears the names of three Lazo men, Rodolfo among them.

Each year in mid-October, members of the Association of Relatives of the Detained, Disappeared, and Executed of Paine travel to the ravine to commemorate the killings. At the event in 2023, Lazo addressed the crowd. She spoke briefly, recounting her memories from the night her family was taken. “Memory will allow us to vindicate our victims, our mothers and ourselves, the children,” she said.

Among Lazo’s most vivid memories is the day she came face to face with the person who directed her family members’ killings, Colonel Andrés Magaña. It happened there, at the execution site, in December of 2015, when, as part of the judicial process, the aging army officer participated in a reenactment of the massacre. Some two dozen actors, wearing white coveralls to preserve the integrity of the crime scene, descended into the ravine while Magaña and a few of the other perpetrators issued instructions, replaying the sequence of events. The families, though permitted to attend, were cordoned off from the perpetrators by barricade tape and a phalanx of police.

Flor Lazo shows a video of the 2015 reenactment at the ravine execution site on her home computer. As part of the judicial process, Colonel Andrés Magaña — who directed the killings — participated in the reconstruction of the massacre of the men from Paine by the Pinochet regime.

The ravine where the men from the Lazo family were executed in October 1973.

As soon as Magaña came within sight of the relatives, however, they erupted with rage. At one point the crowd broke through the cordon, hurling insults and chasing Magaña into an awaiting van. The catharsis was perhaps the only justice the families would ever receive — Magaña died several years later, without ever having served prison time for the killings. For Lazo, though, something lifted that day, as decades of pain emptied out of her. “I have healed a little,” she said, “because I screamed my life out.”

Nevertheless, she still grapples with the grotesque injustice of the killings and their aftermath. At the commemoration in 2023, she stood beside her family’s cross, peering into the ravine and fighting back tears. “The absence of justice made the sorrow even deeper, and made the trauma deeper,” she said. “Because you can’t have justice after 50 years. After 50 years, everyone’s dead. Nobody paid for the murders. So we have to work with the memory, and work with our children and grandchildren so this continues through time, and is never allowed to happen again.”

Fuente

Grave Mistakes: The History and Future of Chile’s ‘Disappeared

A brutal regime hid hundreds of people’s remains. Can new forensic science help find them — and regain public trust?