Following a happenstance case break, detectives in Southern California found the person responsible for an unsolved 1986 homicide of a 19-year-old woman – a serial killer already on death row, Los Angeles county sheriff’s officials said Tuesday.

Cathy Small was working as a prostitute in February 1986 when she was killed, her roommate told law enforcement at the time, sheriff’s Lt. Patty Thomas said at a news conference. Small told her roommate she was meeting a man named Bill who would give her $50 to drive with him from Lake Elsinore to Los Angeles, and she left their home that night wearing a nightgown, Thomas said.

Reading a newspaper days later, her roommate learned of a woman stabbed to death in South Pasadena. Fearing it might be Small, the roommate contacted police and was able to identify her. Investigators were not able to solve the crime, however, and the case went cold.

Some 33 years later, in October 2019, a coroner investigator was checking out the death of a man just across the street from the scene of Small’s killing when he found in the man’s home several items that raised concern, Thomas said. They included “numerous photos of women who appeared to have been assaulted and held against their will, possibly by the decedent,” and a newspaper article about Small’s death, Thomas said.

The Los Angeles County Sheriff’s Department executed a search warrant and DNA testing was done on some of the items from the man’s home to see whether they were a match to Small, but they were not. Though investigators initially considered the dead man a suspect, they concluded he was not connected to Small’s case and was not linked to other crimes.

But upon examining Small’s case file due to the article found in the man’s home, sheriff’s investigators learned that items of evidence in Small’s case, including a sexual assault kit, had never been DNA-tested. In August 2020, Small’s clothing was tested and the results uploaded into a federal database, where detectives connected William Suff to the case, Thomas said.

Suff was on California’s death row at the San Quentin prison, having been convicted of 12 murders in Riverside County. Suff was known as the Riverside Prostitute Killer, or Lake Elsinore Killer.

In May 2022, Suff was transported from San Quentin to Los Angeles, where he confessed to killing Small, Thomas said.