Notorious 'Nightstalker' May Not Have Acted Alone In At Least 1 Killing

LOS ANGELES (CBSLA.com) — Richard Ramirez was one of the nation's most prolific serial killers.

Dubbed the "Nightstalker," he was ultimately convicted in 13 murders after terrorizing Los Angeles and San Francisco from April 1984 until August 1985.

But Monday, more than 30 years after the last murder, San Francisco's police chief says there is evidence suggesting that in at least one killing, Ramirez may not have been acting alone.

Chief Greg Suhr says a handkerchief was found near one of the murder scenes containing the bodily fluids of Ramirez and another man, as well as the blood of the victim.

"There is a handkerchief that was found and there was a second sample on it," he said. "There has been work done, but at least right now, it's under further investigation."

He added: "There is no statute of limitations for homicide, and we in the crime lab are trying to work to see if we can somehow connect this other person in some way to that offense."

Suhr said they know the identity of the second person but did not disclose that information.

The murder in question was the first killing linked to Ramirez, that of 9-year-old May Leung, who was found raped, beaten and stabbed to death in 1984.

Retired Los Angeles County Sheriff's Department detective Lt. Gil Carrillo was the lead investigator in the serial murder case and said that Ramirez never mentioned a second person.

"And at no time in our investigation did we ever find any evidence of a second person," Carrillo said.

Ramirez died on death row in 2013.