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How genealogy is helping Idaho State Police solve cold cases

Posted at 12:50 PM, Sep 25, 2020
and last updated 2020-09-25 14:50:28-04

MAGIC VALLEY — For the protection of the survivor in this case, we have chosen not to identifier her.

On the night of August 4th, 2017, an unnamed Idaho woman in Teton county decided to walk to her bike after a night of hanging out with friends, a walk she had done before, and did not think this time would be any different.

"That is until someone grabbed me from behind as I was retrieving my bike. This person that had grabbed me wrapped his arms around my waist and covered my mouth with his free hand. At first, I didn't struggle because I thought it was one of my friends sneaking up behind me, but then I realized this person was not playing around, and I began to struggle," the survivor said.

The survivor was sexually assaulted, and the following day reported the incident to the police. But even after searching the crime scene, collecting physical evidence, and interviewing witnesses, the case had no leads.

More than two years passed when one of the detectives decided to hand over the evidence to a forensic genealogist.

"The question we had to solve was how do we use genealogy to find this guy," Colleen Fitzpatrick, president of Identifinders International, said.

The process involved using GEDmatch, an online service that compares DNA data from different testing companies, the same platform that also helped identify a suspect in the golden state killer case in California.

Using GEDmatch helped them build a family tree to narrow down the suspect.
"I will tell you it took us two days. It took us two days, and we had 875 people in our tree in two days, and we identified the couple that connected the groups, connected all the matches, and their sons are related to all the matches," Fitzpatrick said.

After narrowing down the search, detectives followed the suspect, Chat Nielsen, where they collected DNA evidence to run more tests.

"At about a week later, I received a report from the state lab. This was report number 8. This report stated that this DNA profile is at least 163 octillion times more likely that Chat Nielsen is the source than if any unrelated individual randomly selected from the general population. I took that as Chat is our guy after two long years," Andrew Foster, one of the detectives on the case, said.

This genealogy DNA testing technique was also used to solve the 1996 cold case murder of Angie Dodge. The case went unsolved for 23 years until police used forensic genealogy to find a suspect, Brian Leigh Dripps, who was later charged with first-degree murder. Another suspect, Christopher Tapp, had already served 20 years for the crime. He was later freed after police arrested Dripps for the crime.

"This is a technique that is solid, it's scientific and that we can implement to help the people of Idaho, and that is so gratifying to our staff," Matthew Gamette, Laboratory Assistant Director for Idaho State Police Forensic Services, said.

Idaho State Police are receiving a grant next week to continue to use genealogy to solve other cold cases throughout the state. They say this will help them significantly since CODIS, the current database they use only contains DNA from people who have been convicted of felonies.

"So in our state, there's a lot of people who are not in CODIS even though they have been arrested and convicted of misdemeanors," Gamette said.

Which is why some of these cases go unsolved. But with incorporating genealogy into DNA testing, anybody who uses services like 23 and me or can upload their DNA to a public access database to help police solve cold cases.

"We were concerned that it might decrease the number of people that are willing to contribute their DNA to a public database, but the exact opposite has happened.

More people are contributing. The new people that are putting their DNA are largely checking the box to allow their DNA to be searched for the purposes of helping solve crime," Gamette said.

Idaho State Police say they plan to invest approximately $3,000 per case from the grant money they will receive next week. They say this will help them solve an estimated 50 cold cases. The $3,000 per case will primarily fund running the genealogy and advanced DNA testing.

"These aren't boxes on a shelf. These aren't nameless individuals. These are people that have real stories, and they've been victimized," Gamette said.