Analysis7 min read

Genetic Genealogy Cases: What It Has Solved and What It Cannot Do

January 20, 2025 · Updated October 5, 2026 · Cory

In June 1996, Brian Leigh Dripps Sr. lived in Idaho Falls, Idaho, across the street from the home of 18-year-old Angie Dodge. Police interviewed him in a neighborhood canvass five days after she was raped and killed in her apartment. Then the case went another direction for more than two decades, and an innocent man went to prison. What finally brought detectives back across that street was a family tree built from strangers' DNA.

That technique is investigative genetic genealogy. A separate post on this site explains how it works and the rules that govern it. This one is about results: what it has solved, and where it has gone wrong or simply run out of road.

The best public count comes from criminologist Tracey Dowdeswell's Forensic Genetic Genealogy Project. Through the end of 2023, it recorded 651 criminal cases solved with the method, counted as victim-offender pairs, involving 318 identified perpetrators. Separately, it recorded 461 unidentified people given back their names, plus three disaster victims. The count starts in 2015, three years before the Golden State Killer arrest made the method famous.

Angie Dodge: a false confession and a false lead

In January 1997, Idaho Falls police questioned Christopher Tapp, then 20. After more than 100 hours of interrogation he confessed, though no physical evidence tied him to the scene and his accounts contradicted one another. In May 1998 he was convicted of aiding and abetting Dodge's rape and murder and sentenced to a minimum of 30 years. He recanted in 2001.

The DNA at the scene was not his, and police kept looking for its source. In 2014 they obtained a court order to search a Y-chromosome genealogy database that Ancestry.com had acquired from the Sorenson Molecular Genealogy Foundation. A sample there, given years earlier by a man named Michael Usry Sr., matched the crime scene profile at 34 of 35 markers. That pointed police to his son, Michael Usry Jr., a filmmaker in New Orleans. Investigators questioned him and took a saliva sample. It did not match, and he was never charged. Usry called the investigation a serious breach of his and his father's privacy.

The tree that found Dripps

In late 2018, Idaho Falls police brought in genetic genealogist CeCe Moore of Parabon NanoLabs, who searched GEDmatch for relatives of the unknown man. The matches led to one couple, Clarence and Cleo Ussery, whose descendants had to include the person who left the DNA. Moore identified six known male descendants. One had lived in Idaho in 1996. Police followed him and collected his DNA, and it did not match.

After about three more months of research, Moore found a seventh descendant the first round had missed: Brian Leigh Dripps Sr. Police collected a cigarette butt he threw from his car window. The DNA matched. Dripps was arrested in May 2019 and confessed. In February 2021 he pleaded guilty to first-degree rape and murder, and in June 2021 a judge sentenced him to 20 years to life.

Tapp's rape conviction had been vacated in 2017 and he was released. He was fully exonerated of the murder in July 2019. In June 2022 the city of Idaho Falls settled his lawsuit for $11.7 million, and the mayor apologized. Tapp died on November 5, 2023, at 47, after a fall in Las Vegas.

Serial cases

The method has named offenders behind long series of attacks. Roy Charles Waller, called the NorCal Rapist, assaulted nine women in Northern California between 1991 and 2006. Crime scene DNA was matched through GEDmatch to one of his relatives, and he was arrested in September 2018. A jury convicted him on 46 counts in November 2020, and he was sentenced to 897 years to life.

In Shelby County, Indiana, a series of violent home invasions and sexual assaults between 1982 and 1985 went unsolved for decades. Parabon's genealogy work narrowed the suspects to Steven Ray Hessler or his brother, and investigators confirmed the lead with DNA from an envelope Hessler had sealed to pay a utility bill. A jury convicted him on all counts in March 2022, and he was sentenced to 650 years.

In Fort Wayne, Indiana, eight-year-old April Tinsley disappeared on April 1, 1988, after going back for her umbrella. A jogger found her body in a ditch near Spencerville three days later. For years afterward, the man who killed her left notes taunting police, including a message written on a barn in 1990 and notes left on girls' bicycles in 2004. In May 2018 a Fort Wayne detective sent the DNA to Parabon. By July 2, Moore had narrowed it to two brothers. Detectives found DNA in John D. Miller's trash that matched, and when they approached him on July 15, 2018, he said April Tinsley's name before they did. Miller pleaded guilty that December and was sentenced to 80 years. He died in a hospital on September 4, 2025, at 66.

Names for the dead

Hundreds of the method's results are identifications, not arrests. In February 1957 a boy was found beaten to death in a cardboard box in Philadelphia's Fox Chase neighborhood. For 65 years he was the Boy in the Box. In December 2022 Philadelphia police announced that DNA and genetic genealogy had identified him as Joseph Augustus Zarelli, who was 4. Both of his parents are dead, and the homicide investigation remains open.

In Allenstown, New Hampshire, a barrel holding the remains of a woman and a girl was found near Bear Brook State Park in 1985, and a second barrel holding two more girls was found nearby in 2000. Genealogy work identified the man the state attorney general's office holds responsible, Terry Peder Rasmussen, in 2017; he had died in prison in 2010 while serving a sentence for a different killing. Three victims were named in 2019: Marlyse Honeychurch and her daughters Marie Vaughn and Sarah McWaters. In September 2025 the DNA Doe Project and New Hampshire State Police identified the fourth as Rea Rasmussen, his daughter, about 3 years old. Her mother, Pepper Reed, has not been seen since the late 1970s.

On April 11, 1975, a fisherman found the body of a teenage girl in the Mississippi River in Clinton County, Iowa. She had been shot in the head and was about 10 weeks pregnant. In October 2025, 16 volunteer genealogists from the DNA Doe Project worked her case over a weekend. In June 2026 the project announced her name: Cheryl Lynn Edwards, 15, of Waukegan, Illinois. The sheriff's office says it can now investigate her killing.

In November 2000 the dismembered body of a teenage girl was found on the grounds of the Soldiers' Home in Chelsea, Massachusetts. Eugene McCollom is serving a life sentence for her murder, yet for 26 years no one knew her name. On June 3, 2026, prosecutors announced that FBI investigators had used genetic genealogy to find her brother, and DNA confirmed she was Tiffany Bradley, 16, of Allentown, Pennsylvania.

What it cannot do

It cannot find anyone whose relatives have not opted in. Since May 2019, GEDmatch has shown police only users who chose to allow it. If no cousins from your family have uploaded, there is no tree to build.

It produces a lead, not proof. Every case above ended with a conventional DNA comparison on a sample from the actual person. The Dodge case shows why. The first tree was right about the family and wrong about the man for months, and an earlier Y-chromosome search put an innocent filmmaker under suspicion for something he had nothing to do with.

It cannot put the dead on trial. Zarelli's parents and Rasmussen were gone before anyone had names. An identification answers who, but no court ever tests it.

Its methods can be challenged in court. Matthew Nilo, a lawyer, was arrested in May 2023 and charged with sexually assaulting women in Boston's Charlestown and North End neighborhoods in 2007 and 2008. He has pleaded not guilty. Investigators say genetic genealogy led them to him, and FBI agents then collected items he had used at a Manhattan restaurant in 2023. His lawyers argue the DNA was taken without a warrant. They also say the FBI searched MyHeritage, which they contend federal policy bars, and at a 2025 hearing prosecutors acknowledged the FBI had not documented what it found there. As of a June 2026 hearing in Suffolk Superior Court, the judge had not ruled on the motion to suppress, and no trial date had been reported.

Taken together, the record is strong. Hundreds of offenders named, hundreds of people buried under their own names again, and at least one wrongly convicted man cleared by the same tree that found the real killer. It is also a record of tools that work only when strangers have shared their DNA, that still depend on old-fashioned confirmation, and whose rules are still being argued in courtrooms.

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