Suspect identified in 1979 cold case murder of Sunnyvale security guard
SUNNYVALE – Using DNA analysis, authorities in the South Bay said they have solved a cold case murder of a security guard in Sunnyvale after more than four decades.
According to the Sunnyvale Department of Public Safety and the Santa Clara County District Attorney's Office, Samuel Silva of Colorado has been linked to the killing of 18-year-old Estella Elena Mena.
Silva died in 2008 while in prison on federal gun charges. Authorities said he had a lengthy criminal history which included manslaughter, attempted murder, assault with a deadly weapon and rape, along with firearms offenses.
"There is no statute of limitations on murder or our attention. We never forget," District Attorney Jeff Rosen said in a statement Thursday. "We don't forget the crime or the criminals. We don't forget the victims, ever."
On October 27, 1979, Mena was guarding an office building on the 400 block of De Guigne Drive when she was stabbed multiple times during an attempted sexual assault. The suspect fled when an office worker interrupted the attack.
In the years following the murder, there were no leads and the case went cold. Mena's killer went unidentified until this year, when a DNA analysis by the Santa Clara County Crime Lab of blood found on the victim's clothing and shoes was linked to Silva.
Silva's DNA had been collected and uploaded to the CODIS national DNA database in 2006, prosecutors said.
Prosecutors said Silva, who was 18 at the time of the killing, had been staying with family in Santa Clara County and may have met Mena while they worked at Great America. He fled back to Colorado after her murder.
According to the DA's office, the case was solved with the help of their Cold Case unit, which is comprised of a prosecutor, criminalist and two DA investigators. Since 2018, the unit has solved 16 cold case homicides and 10 sexual assaults.
On Thursday, the Cold Case unit announced a hotline for the public to send in information about old and unsolved murders. Anyone with information is asked to call (408) 792-2466 or email coldcasetips@dao.sccgov.org.
