Woman’s death posed mystery since 1988. A strand of hair cracked California cold case
Diane Dahn was stabbed to death in her California home in 1988, authorities said.
A strand of hair helped crack her case almost 34 years later.
Dahn’s body was found in her apartment in Santee by a co-worker, the San Diego County Sheriff’s Department said in a news release.
Santee is about 18 miles northeast of San Diego.
Her son was wandering around the apartment complex, and Dahn had been bludgeoned and stabbed, deputies said.
She died from stab wounds to her chest, an autopsy showed, and her death was ruled a homicide.
Detectives worked to identify a suspect after her death but could not find one, deputies said.
DNA was found under Dahn’s fingernails and tested in 2000 and 2001, but deputies said they could not match the samples to someone.
In 2010, detectives processed a hair strand that was found in her hand and developed a profile with it, though it didn’t lead to a match quite yet.
A crime team then used “investigative genetic genealogy” to test the DNA in 2020. They identified Warren Robertson as a suspect a year and a half later.
Additional DNA testing on unknown DNA found under Dahn’s nails was also matched to Robertson, authorities said.
Robertson and Dahn lived in the same apartment complex in 1988, deputies said, but it wasn’t confirmed if they knew each other.
He moved to Lakeside shortly after her death before moving to Indiana in late 1989, deputies said.
He died on Nov. 25, 1999, in a house fire, authorities said. He was 39.
Dahn would have been 63 years old.
This story was originally published March 17, 2022 at 1:25 PM with the headline "Woman’s death posed mystery since 1988. A strand of hair cracked California cold case."
