Summary

On May 28, 1976, deputies were dispatched to the scene of a suspicious death near Aptos Village Park in Santa Cruz County, California. There, they discovered the body of a young woman. The death was quickly ruled a homicide, and the victim was identified as Karen Percifield. She was only 25 years old. At the time, detectives collected forensic evidence from the crime scene and pursued numerous investigative leads, but the case eventually went cold when no suspects could be definitively linked to the crime.

More than forty years later, in 2019, Santa Cruz County Sheriff's investigators revisited the case and submitted several items of evidence to the California Department of Justice Bureau of Forensic Services for traditional forensic DNA testing. A male DNA profile was successfully developed from the evidence, but the individual was not in any criminal DNA database, leaving investigators without a name.

In the fall of 2023, the Santa Cruz County Sheriff’s Office submitted forensic evidence to Othram in The Woodlands, Texas so that a DNA profile could be developed from the forensic evidence. Othram scientists successfully used Forensic-Grade Genome Sequencing® to build a comprehensive DNA profile for the unknown individual. Othram’s in-house forensic genetic genealogy team used the profile to generate new investigative leads in the case.

Through this process, investigators used these new leads to identify Richard Sommerhalder as the person responsible for Karen Percifield’s murder. Back in 1976, Richard Sommerhalder had been considered a person of interest in the case, but there was not enough evidence at the time to pursue charges. Just months after Karen’s murder, in September 1976, Sommerhalder was arrested for two other murders in Santa Cruz County. He served eight and a half years in prison before being paroled and moving out of California. Years later, as detectives sought to revisit his involvement in Karen’s case and attempt to collect a reference DNA sample, they discovered that Sommerhalder had passed away in 1994.

While Sommerhalder will never face trial for this crime, detectives were able to bring a measure of resolution to Karen’s family. “No matter how much time has passed, we will never stop seeking the truth,” said Sheriff Chris Clark. “Advances in DNA technology continue to provide new opportunities to deliver justice and closure to victims and their families. This case is a powerful example of how those advancements can give us the answers we’ve been searching for.”

Santa Cruz County District Attorney Jeff Rosell echoed the sentiment: “Despite the passage of time and the death of the perpetrator, the closure that solving this murder brings to the Percifield family is incredibly important. The Sheriff’s Office is to be commended for their diligence and commitment to solving this crime.”

Members of Karen’s family also shared their gratitude. Her daughter said, “To the detectives, and forensic team, I appreciate them not giving up. This has been weighing on me my whole life, not having a memory of my mom and just wondering who it could have been, this just means so much. I’m just so grateful you didn’t give up.” Her sister added, “It’s nice to know this is finally not an open case, even though it was closed in my mind. It just proves that DNA is a good vehicle to solve these things and put things to rest. I was so young then and wasn’t equipped to understand everything and I’m just so grateful it’s finally over.”

This case is a reminder that every piece of preserved evidence has the potential to unlock long-awaited answers. If you’d like to support efforts to solve more cases like Karen’s, consider contributing your DNA data to the DNASolves database which aids law enforcement in identifying perpetrators and giving families the answers they deserve.

This identification represents the 59th publicly announced case in California where investigators have used Othram's technology to identify an individual.