LA Forensics: The Chinatown Widow

Four more years dragged on. Fingerprint technology was constantly improving and making limited matches. LAPD Detective Randy Adair ran the print every few months, hoping for the impossible.

Detective Randy Adair

"He kept running the print. A dogged detective who wouldn't give up, who promised the adult children of Donna Li that he was gonna solve their mother's murder," prosecutor Rose said.

Finally Adair retired. He had been on the case since its inception. One night he received a welcome phone call.

Mike Zehr as Detective Adair

"I'll never forget," he said. "I was at home. My phone rang and it was (a detective) who said, 'Randy, we matched your print on this case.' I said, 'Yeah, it's been like six years, you know.' I was real happy that it worked."

Jack Gus Farnum

The suspect was Jack Gus Farnum, a 24-year-old drifter. He was in California's Folsom Prison on a murder conviction. Investigators traveled up there to obtain a hair and blood sample and a clean set of fingerprints. It wasn't going to be easy.

"He became so uncooperative that the prison officials had to hold him down, tie him down, in order to cut a piece of his hair, to take a sample from his mouth, to take his blood sample and again they printed him," Rose said.