After years of diligent work, Sunnyvale Department of Public Safety (DPS) officers say they have solved a more than 40-year-old cold case.
On Oct. 16, 1979, 18-year-old Estella Elena Mena was working as a security guard at a business at 444 De Guigne Drive when she was assaulted. Investigators arrived on scene and found her in the lobby of the business suffering from multiple stab wounds.
Mena was taken to a local hospital, but she did not survive. At the time, blood evidence at the scene helped the Santa Clara County Crime Laboratory develop a DNA profile of the suspect. It went unmatched for 44 years.
In October 2022, Sunnyvale resubmitted the DNA profile for Forensic Investigative Genealogy and developed new leads.
According to the news release by Sunnyvale DPS: “Sunnyvale detectives conducted multiple surreptitious DNA collection operations. Ultimately, the source of the blood at the scene was positively identified and eliminated from suspicion. Additional evidence testing was conducted by the Santa Clara County Crime Lab and a second male DNA profile was identified on items directly connected to the victim.”
Investigators searched for that DNA in CODIS and identified Samuel Silva, a former resident of Sunnyvale. Silva was born March 29, 1961 and died in Colorado in 2008. Investigators say he had a criminal history that included sexual assault and violent crime.
Sunnyvale DPS says despite Silva’s death, the investigation continued. Ultimately, DPS investigators, along with the Santa Clara County District Attorney’s Cold Case Unit, closed the homicide case and named Silva as the murderer.
This is not the first cold case DPS investigators have solved in the past few years. Last year, Sunnyvale DPS arrested Gary Gene Ramirez in Maui and brought him back to the Bay Area to face charges for the stabbing death of Karen Stitt in 1982.