https://www.nbcnews.com/news/us-news...g-dna-n1070181

Authorities in the Milwaukee area solved the 35-year-old murder and rape of Traci Hammerberg by connecting a DNA profile to a second cousin registered in a genealogy database.

Philip Cross, a Wisconsin man who died of a drug overdose in 2012, was identified as a suspect in the 1984 cold case out of Port Washington, the Ozaukee County Sheriff's Office announced Tuesday. Traci was killed Dec. 15, 1984, after partying with her friends and leaving after midnight to walk almost four miles home.

Traci's body was found brutally beaten and partially naked in a driveway in the early morning. An autopsy determined that the 18-year-old had been raped, strangled and had her head bludgeoned with a metallic object.

Though authorities at the time were able to compose a DNA profile from semen found on Traci's body, a suspect was never identified.

Police began looking into genealogy databases in March in the hopes that the DNA profile they created in 1985 might match with a potential relative of Traci's murderer. Investigators found a potential second cousin who could lead them to their killer.

Authorities then began to build out the cousin's family tree and began to eliminate family members from a list of suspects. Cross was identified by authorities in August as someone who could fit the profile and could potentially have been in the Port Washington area at the time.

The DNA profile obtained from semen found on Traci's body in 1984 was a confirmed match to a DNA card created for Cross during an autopsy after he died of a drug overdose in Milwaukee in 2012.