Since 1989, 3,615 people convicted of crimes in the U.S. have been exonerated and freed after their conviction was reversed. Postconviction DNA testing played a part in 606 of these cases.
Brothers Robert and David Bintz became new additions to this list last September after investigative genetic genealogy (IGG)—which relies on genealogical and genetic data to reverse engineer family trees—helped to reveal the true perpetrator of the 1987 crime they had been convicted of. 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 cleared with the help of IGG. Although the revolutionary investigative technique has, since its inception in 2018, been used primarily to 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. This case is also a testament to the need for legislative reform to address injustices in the 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 be a DNA match to a blood spot on Lison’s dress. For 11 years law enforcement was unable to identify a viable suspect in the case.
Then, in 1998, while David Bintz was serving time in prison for an unrelated crime, his cellmate claimed David had made incriminating statements about Lison in his sleep. The cellmate (and others) said David also implicated his brother, Robert. Under interrogation, David confirmed the statements but also denied involvement in the crime. Law enforcement reviewed notes from the initial investigation and 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 David’s alleged confession and this motive as evidence, the brothers were tried for Lison’s murder.
The dual exonerations of the Bintz brothers in Wisconsin demonstrate investigative genetic genealogy’s power as a tool of justice.
Prosecuting attorneys in the Bintz brothers’ trials knew that the only DNA evidence in the case, which came from semen and blood on the victim, excluded Robert and David. Thus, they argued that both substances were unrelated to Lison’s death. Despite the absence of 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, who had served 20 years after a wrongful conviction for murder, and the group recognized its potential to help the Bintz brothers.
Working with 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 DNA information for personal research. A subset of those individuals have opted to allow their data to be compared with crime scene profiles and those developed from unidentified human remains.
In the summer of 2023 GNIP turned this work over to the Ramapo College Investigative Genetic Genealogy Center, which was founded in 2022 partly to apply the powerful investigative tool of IGG to more cases of wrongful conviction. In just two days a small group of staff and students in the center’s 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. The team traced the family tree and 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 it was 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 the Good Times Tavern matched Hendricks as well.
There could no longer be any doubt about who raped and murdered Lison. Last September, Wisconsin prosecutors joined GNIP 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 adoption for this purpose. Skepticism of any new investigative or forensic method is justified, but the questions 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, as well as a database of those who have passed the exam and met other requirements.
For the Bintz brothers, the path forward will not be easy. Unlike prisoners who are released after serving their full sentence, those who are suddenly exonerated don’t have access to any services that could ease their reentry into free society. And for their quarter of a century in prison, Robert and David will each receive compensation of just $25,000, the limit allowed by Wisconsin law. The Innocence Project recommends, and many states provide, a minimum of $70,000 per year served.
We encourage attorneys fighting to free the innocent to embrace IGG, and we urge the Wisconsin legislature to use the lesson of these cases to align the state’s 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 of Scientific American.