Guam Symposium: how the Golden State Killer case was solved after 43 years

A notorious cold case once thought unsolvable was front and center today at Guam Community College, as Day 2 of the Regional Forensic Science Symposium brought together top legal minds and law enforcement from across the Pacific. The Golden State Killer case, cracked using cutting-edge DNA technology, served as a powerful lesson in how science and justice intersect.
It was a case that haunted California for decades, a masked predator who eluded authorities while leaving a cold trail of bodies, until science caught up. Former Sacramento County sheriff’s deputy Gail Wilcynski recalls living through that fear.
"I was in college in Sacramento in the ‘70’s, and it was sheer terror every night. Every night, because three nights a week, someone’s [home] was being broken into and raped. This went on and on for years and they didn’t catch him," she said.
On the second day of the symposium, former Sacramento district attorney Anne Marie Schubert virtually walked investigators, prosecutors, and forensic experts through the takedown of the Golden State Killer. The case was solved through a pioneering technique called forensic investigative genetic genealogy, using DNA from the crime scene and public genealogy websites.
She said, "You're using genealogy to develop investigative leads, whether it’s on unsolved crimes or unidentified missing persons. Then law enforcement is basically taking that information and trying to match it with somebody."
The 2018 arrest of former police officer Joseph James Deangelo stunned the country and redefined forensic investigation. "We have the capacity now to if you have DNA on a violent crime, we have the potential of solving well over 90 percent of those cases. That to me is what’s so exciting," she said.
Schubert says the case was unsolved for 43 years, with more than $10 million in resources spent and over 650 investigators from 15 different law enforcement agencies involved— all producing zero suspects. But with this new technique, she says it took just $217 to identify one suspect in just 63 days.
"So that is the power of the tool. Think about the resources, think about the ability to identify people quickly. Steve Cramer often said, ‘we have the power to eliminate the word serial–serial rape or serial killer– from our vocabulary when it comes to solving crime now," she added.
In 2020, Deangelo pleaded guilty to 13 counts of murder and is serving life in prison without parole. For Pacific island nations in attendance who often face limited resources, it sent an empowering message that breakthroughs don’t just come from big cities.
As Guam Chief Medical Examiner Dr. Kenny Su puts it, "This experience reminds us that we law enforcement need to work together for homicide cases, to make it work."