MERIDIAN, Idaho (KMVT/KSVT) An Idaho Falls man is free after being exonerated for murder, using genetic genealogy to find the real killer.

But what exactly is it?

It’s taken down a prolific serial killer, and freed Chris Tapp, an innocent man from jail.

Idaho State Police Forensic Services Lab director Matthew Gamette said there’s a more accurate term for it.

“Molecular genealogy. You’re looking at a technology that has been implemented, it’s called SNPS. And what they’re looking at is, they’re looking at developing a specific DNA profile, that they can then use through genealogical databases that are being developed all over the country,” Gamette explained.

One of those databases is GEDmatch.

This was the database that cops used in both the Golden State Killer case, and the Angie Dodge murder in Idaho Falls, for which Tapp was wrongfully convicted.

“They’re looking at these familial relationships, they’re trying to find people that they didn’t know existed before, and then through that information, they would provide a sample back to us from someone they think might be a suspect on the case, and we would look to confirm, or not confirm the results of that genealogical analysis done, for the most part trained genealogists,” Gamette explained.

DNA also played a part in the Dodge case, according to Gamette.

“DNA played a huge role in this case. One of our analysts, Cyndi Hall, was the one that worked this case for us, and she had multiple samples,” Gamette said.

They initially had developed a DNA profile that was uploaded into the national DNA database, Gamette states.

“And it sat there without hitting to anyone. So we knew initially that we had not identified the individual that the sample was from. So at that point we were waiting for someone to be arrested or convicted of something that would match to the sample that was already uploaded into the database,” Gamette said.

So after years of waiting, investigators turned to molecular genealogy.

“They were able to, through family lines, look for other individuals that might be related. They used genealogical work to try to identify those. They then identified a potential suspect, they collected a reference sample, or in most cases that’s a cheek swab or a blood sample directly from the individual, they sent that into our laboratory here, we processed it for a DNA profile, and then we were able to make a match,” Gamette said.