‘Genetic geneology’ is helping crack cold cases in Alaska. Here’s how it works.

The Shelley Connolly murder case had stalled for more than four decades. But on Tuesday, authorities announced a breakthrough — they’d arrested a 62-year-old Oregon man and charged him with killing Connolly near Anchorage in 1978.

It was the second time this year that Alaska investigators used new DNA technology called genetic genealogy to crack a cold case. To help with the testing, the state hired a Virginia-based company called Parabon NanoLabs. The company analyzes crime scene DNA and tries to match it to databases supplied by people who have taken ancestry tests, or given other types of genetic samples.

Steve Armentrout, Parabon chief executive, says it’s a new science that’s expanding quickly.