WHITTIER — A suspect in the 1981 rape and murder of a young Whittier woman in her own home was in court Friday after DNA evidence linked him to the 30-year-old cold case, authorities said.
Joseph Allan Thornton, 50, was living in the City of Auburn when investigators, armed with DNA evidence linking him to the crime scene, arrived at his home and arrested him Monday for the June 27, 1981 rape and slaying of 21-year-old Blanca Stella Negrete , Whittier police Lt. Kent Miller said.
The arrest came as bittersweet news to family members of Negrete, who have spent the past three decades without answers in her slaying.
“This brings back horrible memories for them, but they’re also excited that it’s led us to a suspect, so there’s some closure for them,” Miller said.
Negrete worked at what is now Presbyterian Intercommunity Hospital at the time of her slaying, police said. It was not clear what, if any, relationship existed between Negrete and Thornton.
Negrete was found strangled to death inside her apartment, where she lived alone, in the 7600 block of Washington Avenue, Miller said.
Evidence, including DNA from a sexual assault, was collected at the time, though technology that would enable police to link it to a suspect did not exist, Whittier police said Friday in a written statement.
“At the time of the homicide, Whittier Police detectives exhausted all leads and were not able to identify a suspect,” according to the police statement.
In May of 2010, Whittier police detectives re-opened the case and discovered that evidentiary DNA was possibly among the evidence collected in the case, officials said.
The DNA sample was sent to the Los Angeles County Crime Lab, and on Jan. 19, detectives were notified that the sample was sufficient to be used for DNA comparison.
“The information was entered into (a database) and the DNA matched to a person named Joseph Allen Thornton,” the statement said.
Thornton’s DNA was entered into the database because of a previous felony conviction for domestic violence, Miller said.
Since discovering the DNA match, Miller said, investigators have been working to track down and arrest Thornton.
The investigation took place both locally and as far away as Topeka, Kansas, where Thornton had resided for may years.
He has worked for the past three decades primarily as a house painter, Miller said.
A break in the case came Monday, when Whittier police located Thornton in Auburn and arrested with without a struggle with the help of Placer County sheriff’s deputies.
According to county booking records, Thornton was being held without bail pending his initial court appearance.
PHOTOS of Joseph Thornton and Blanca Negrete courtesy of the Whittier Police Department.