DNA on chewing gum leads to conviction in 1980 cold case

Robert Plympton, 60, was found guilty last week of murdering student Barbara Tucker in 1980 after sexually assaulting her. They caught him by using genetic tests on DNA from the crime scene, narrowing down suspects based on presumed traits ("there was extremely high likelihood that the person who murdered and raped Barbara had red hair") and getting DNA samples from them.

Investigators used that information to begin surveilling Plympton and were able to collect a wad of chewing gum that detectives witnessed him spit out, the DA's office said. DNA pulled from the gum matched the profile from the autopsy swabs and Plympton was arrested on June 8, 2021.

"I was just totally taken a back. It was amazing," Tucker's sister, Susan Pater, told CNN affiliate KATU in an interview at the time. "It was really good news. I'd given up," Pater said.

Moore calls the case "one of the highlights of my career in genetic genealogy."

If it all sounds like voodoo forensics a la blood sprays and bite marks, remember that all it was used for is to get the lead.