FREMONT — New DNA technology that led to the arrest of the Golden State Killer has led to the arrest and charging of a man in Arizona in a 1990 Fremont stabbing death, police said Thursday.
Russell Anthony Guerreo, 52, is accused in the Dec. 17, 1990 killing of Jack Upton, then 30, who was found slain in his apartment in the 38700 block of Tyson Lane.
Police said Thursday they are still unsure of a motive for the killing and that they have not been able to find any prior connection between Upton and Guerrero.
Police said Thursday that Upton was a well liked and respected manager at a Fremont Safeway store and that his body was found after a missing person’s report was filed because he had not shown up for work for several days.
His 1985 Nissan 300 ZX, which had been stolen from the apartment complex, was found Dec. 24, 1990 in the parking lot of a Thousand Oaks’ mall.
Police said blood located in the apartment and in the car belonged to an unknown person.
A DNA profile was eventually made and uploaded into a national DNA index system which at the time did not come back with any matches.
The case was investigated over the years by several Fremont detectives and in 2016 was taken over by the newly created Cold Case Homicide unit headed by Detective Jacob Blass.
Police said in April 2018 new DNA technology was brought to the forefront with the arrest of the suspected Golden State Killer. Fremont police detective reached out to Parabon NanoLabs, the same lab which assisted in the Golden State Killer case and requested assistance in the Upton killing.
The DNA from the Upton case was processed and compared against existing genealogical DNA profiles which Parabon NanoLabs has access to and that search, along with other evidence, led to Guerrero as a potential suspect, police said.
Fremont Lt. Mike Gebhardt said “the DNA blew us away” since Guerrero’s name had never come up before in the investigation, even with numerous interviews of people who knew Upton.
Police learned Guerrero was married and living in Tempe, Arizona. Fremont detectives went there, placed Guerrero under surveillance and were able to obtain a DNA sample from him for comparison. It was subsequently found to be a match from the blood found in the apartment and car, police said.
Guerrero was charged Jan. 17 with murder by the Alameda County District Attorney’s Office and he was arrested Tuesday in Chandler, Arizona by Fremont detectives. Search warrants were served on Guerrero, his home and vehicle and evidence collected.
He is in custody in Arizona and is in the process of being extradited to Alameda County.
Check back for updates.