John Arthur Getreu, who has been in custody in Santa Clara County, California, since November for a 1973 murder, was charged Thursday for a separate murder due to evidence from genetic genealogy testing.

Getreu, 74, a carpenter who previously worked for Stanford University, was originally arrested for the 1973 murder of 21-year-old Leslie Marie Perlov. Perlov's body was discovered dead from ligature strangulation after she had last been seen leaving the Stanford campus.

The second charge involves the murder of 21-year-old Janet Taylor, who disappeared in 1974 while hitchhiking from the Stanford campus to her home in Northern California. Her body was found the next day on the side of a nearby highway, also dead from strangulation.

Police revisited the clothes Taylor was wearing at the time and tested the foreign DNA. Like Perlov, the DNA was identified as Getreu’s and has resulted in more charges.

Taylor and Perlov were among the four people who were murdered in 1973 and 1974 near or on the Stanford campus.

A convicted rapist, Getreu could be connected to other murders.

"Many of the records on Getreu are old and/or incomplete, so we are still researching his past," Assistant San Mateo County Sheriff Greg Rothaus said at a press conference. "We are actively looking into areas where he has lived in the past and communicating with those agencies too."

tape police This image shows police tape around an apartment building where police found seven people dead in Grapevine, Texas, Dec. 25, 2011. Photo: Ronald Martinez/Getty Images