A retired police officer, who investigators believe is the "Golden State Killer", was charged on Thursday with four more counts of murder in Santa Barbara, California. They got lucky: a match with family members led them to identify and arrest Joseph James DeAngelo.
Joseph James DeAngelo, 72, was charged with killing two people - Robert Offerman and Alexandria Manning - on December 30, 1979, and with the 1981 killings of Cheri Domingo and Gregory Sanchez in Goleta.
"Violent cold cases never grow cold for victims or their loved ones", Dudley said.
Rhonda Wicht, 24, and her son Donald, 4, were murdered in 1978.
The case of the Golden State Killer, linked to at least 50 rapes and 12 murders between 1976 and 1986, had gone cold - although investigators believed they had a reliable sequence of the perpetrator's DNA.
Holes suggested the encounter may have encouraged the killer to rethink his tactics as he committed one more known murder five years later.
It is unknown when DeAngelo will appear in a Santa Barbara County courtroom to face the charges since he is facing murder charges in several other counties, including Sacramento, Ventura, and Orange counties.
In a stunning development nearly 40 years after the case went cold, DeAngelo was taken into custody on April 24 when prosecutors used advanced forensic DNA technology and genealogical information posted to a public website by a distant relative to identify him. He was arrested last month and remains jailed in Sacramento County.
DeAngelo's attorney, Diane Howard, did not immediately respond for comment.
The charges filed by Dudley's office could result in the death penalty or life in prison without parole upon conviction.