Genetic Genealogy Can Stop Violent Criminals and Free the Wrongly Convicted

Genetic Genealogy Can Stop Violent Criminals and Free the Wrongly Convicted

By David Gurney & James R. Mayer

Since 1989, 3,615 individuals convicted of crimes have been exonerated in the U.S., freed after their conviction was reversed. Post-conviction DNA testing played a part in 606 of these exonerations.

Brothers Robert and David Bintz became the latest additions to this disturbing list on September 25, after investigative genetic genealogy (IGG)—which relies on genealogical and genetic data to reverse engineer family trees—helped reveal the true perpetrator of the crime. In many ways, their cases are typical of other wrongful convictions: false confessions and jailhouse informants provided the primary evidence against them at trial. Yet their stories are unusual because of the underlying investigative method essential to their exonerations.

The Bintz brothers are only the third and fourth individuals exonerated with the help of IGG. While the revolutionary investigative technique has, since its inception in 2018, primarily helped identify human remains and perpetrators of violent crimes, the dual exonerations of the Bintz brothers demonstrate its power as a tool of justice generally. It’s one that more wrongful conviction organizations should pursue. The case is also a testament to the need for legislative reform to address injustices in Wisconsin’s criminal legal system, particularly for those who are found innocent after serving time in prison.

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On August 3, 1987, Sandra Lison—a mother of two—disappeared from the Good Times Tavern in Green Bay, Wis., where she worked as a bartender. The following morning, hikers discovered Lison’s body in a nearby forest. She had been strangled, and police noted the presence of semen, which was later found to match a blood spot found on Lison’s dress. For 11 years, law enforcement was unable to identify a viable suspect in the case.

Then, in 1998, while serving time for an unrelated crime, David Bintz’s cellmate claimed that David had made incriminating statements about Lison in his sleep. The cellmate (and others) claimed that David also implicated his brother, Robert, in the crime. Under interrogation, David confirmed the statements, even as he also denied involvement in the crime. Reviewing their notes from the initial investigation, law enforcement discovered that David and Robert had bought beer from Lison on the night of her disappearance and had been upset about the price difference between a case of beer and four six-packs. With this confession and motive evidence, the two brothers were each tried for Lison’s murder.

At trial, the prosecution knew that the only DNA evidence in the case, which came from semen and blood on the victim, excluded the Bintz brothers. Thus they argued that both substances were unrelated to Lison’s death. Despite no physical evidence tying them to the scene, the brothers were each convicted and sentenced to life in prison.

In 2019 the Great North Innocence Project (GNIP) took on the case of Robert Bintz, convinced that the DNA evidence from the crime scene was the key to his exoneration—and to the identification of the true perpetrator.

Just a year before, IGG had made headlines for helping to identify Joseph James DeAngelo as the Golden State Killer and Marcia King as the Jane Doe previously known as Buckskin Girl. GNIP had followed the development of IGG as it played a role in the 2019 exoneration of Christopher Tapp, and the group recognized its potential to help exonerate the Bintz brothers.

Working with the forensic technology firm Bode Technology, GNIP developed an advanced genetic profile from the crime scene evidence. That profile was uploaded to two consumer genetic genealogy databases, FamilyTreeDNA and GEDmatch, where members of the public can upload their genetic profiles for personal research. A subset of those individuals have opted to allow their profiles to be compared with crime-scene profiles and those developed from unidentified human remains.

In the summer of 2023, the IGG work was turned over to the Ramapo College Investigative Genetic Genealogy Center (IGG Center), which was founded in 2022 partly to bring this powerful investigative tool to more cases of wrongful conviction. In just two days, a small group of staff and students in the inaugural “IGG Bootcamp” reverse engineered the family tree of the individual who had left the DNA at the crime scene in Green Bay 36 years earlier. Descending the family tree, the team landed on three brothers who fit all the genetic and genealogical evidence. One brother stood out: William Hendricks, who had been convicted of rape and had been released from prison just seven months before Lison’s murder.

Hendricks died in a mental hospital in 2000. In the summer of 2024, his body was exhumed, and ultimately Bode Technology developed a genetic profile from his remains. When compared with the crime scene evidence, the result was unequivocal: William Hendricks had left the blood and semen on Lison. Investigators in Wisconsin went back to the evidence in the case and discovered that fingerprints on an empty cigar box found behind the counter at Good Times Tavern matched Hendricks as well.

There could no longer be any doubt who raped and murdered Lison. In September Wisconsin prosecutors joined the Great North Innocence Project and the Wisconsin Innocence Project (which represented David) in seeking the release and exoneration of the Bintz brothers. Within days, they walked out of prison.

There are many similar cases that IGG could help resolve. Yet concerns about the technique may be slowing its use to help free the innocent. Skepticism of any new investigative or forensic method is justified, but the concerns raised about IGG have largely been answered. Today, there are a host of IGG practitioners and teams who have developed robust policies and procedures around use of the technique. The Investigative Genetic Genealogy Accreditation Board has promulgated standards and a code of ethics for the field and will soon offer an accreditation exam and database of those who have passed the exam and met other requirements.

For the Bintz brothers, their path forward will not be easy. Unlike guilty prisoners who are released after serving their time, no reentry services are available to those suddenly exonerated. And for their quarter century in prison, Wisconsin law limits their compensation to $25,000 each.

By contrast, the Innocence Project recommends, and many states provide, a minimum of $70,000 per year served.

We urge attorneys fighting to free the innocent to embrace IGG, and we urge the Wisconsin legislature to use the lesson of these cases to align their compensation statute with the amount recommended by the Innocence Project.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those ofScientific American.