Police in Idaho have used a controversial emerging DNA technique that relies on public genealogy databases to make an arrest in the 1996 killing of 18-year-old Angie Dodge. Idaho Falls Police say they've arrested Brian Leigh Dripps, of Caldwell, Idaho, on rape and murder charges.

After using genetic genealogy to develop the 53-year-old Dripps as a suspect, police used a discarded cigarette butt to determine that his DNA matched an unidentified DNA profile culled from evidence left at Dodge's Idaho Falls apartment, where she was sexually assaulted and stabbed, Idaho Falls police chief Bryce Johnson said.

Dripps was arrested during a traffic stop in Caldwell Tuesday and later confessed to the crime during an interview, Johnson said. Police didn't reveal a motive. But Johnson said Dripps was living across the street from Dodge at the time she was slain and was an acquaintance of hers.

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Speaking Thursday, Dodge's family thanked the police department for their persistence over the decades.

"I can't even express how hard this journey has been, and the hundreds of people who have been affected by one person's choice to take my daughter's life," said Dodge's mother Carol.

Genetic genealogy had expanded in popularity among law enforcement since it was used to identify the suspect in California's notorious "Golden State Killer" case, but it has also raised a host of privacy concerns. The technique utilizes public DNA databases, where users who have obtained their own DNA profiles from commercial companies such as Ancestry.com and 23andMe can upload them to expand their search for relatives.

Cold case investigators have used unidentified suspect DNA profiles to search the public databases of genetic blueprints in the hopes of finding a "partial match" — a relative — and developing a family tree to narrow down the search for a suspect. In the Dodge case, Idaho Falls police used Parabon Labs, a private lab based in Virginia, to conduct the genetic analysis and provide them with new leads. Six possible suspects turned up, but none turned out to be a match, Johnson said. The lab's genetic genealogist eventually came up with Dripps' name through his grandmother's online obituary, and police staked out his Caldwell home to obtain the cigarette butt they used to make the match, Johnson said.

Brian Leigh Dripps KBOI

It wasn't the first time the department searched a public DNA database in the case, but their first attempt led them to wrongly identify a New Orleans filmmaker as a suspect in the case, "48 Hours" reported in their investigation "The DNA of a Killer."

Dodge's murder case remained open after another man who confessed to aiding the crime, Chris Trapp, was convicted and spent years in prison, because his DNA didn't match the crime scene evidence. Defense attorneys have claimed the confession was coerced, and Trapp was eventually freed.

Dripps has been booked into jail in Canyon County and was expected to be transported back to Bonneville County and held without bail, reports the Idaho Statesman. It wasn't clear whether he had a lawyer to speak on his behalf.