SAN FRANCISCO (NewsNation Now) — Nearly 50 years after a serial killer dubbed the “Doodler” terrorized San Francisco’s gay community, police announced an increased $200,000 reward for details leading to his capture.

Police believe the killer stabbed at least five men to death from early 1974 to late 1975.

In January, San Francisco police identified a potential sixth victim as Warren Andrews, who was assaulted at Land’s End in April 1975, police said. He was found unconscious and died several weeks later.

The suspect became known as the “Doodler” after a victim who survived an attack told police the man was doodling while they talked at a late-night diner and said he was a cartoonist.

Police have since released a pair of images that showed a 1975 sketch of the man and an “age-progression” showing what he might look like now.

Kevin Fagan, a reporter for the San Francisco Chronicle, said the killer may have far more victims than officially reported — as many as 17. 

“[Gay men] were getting beaten,” Fagan said. “There were more stabbings and shootings and beatings than I could count when I was doing clip searches. And some of the cops that I talked to back in the day said they’d come in and they couldn’t solve them and they’d shelve them.”

An Associated Press story from 1977 quotes police as saying the suspect at the time could not be charged because three survivors, including a “well-known entertainer” and a diplomat, were reluctant to “come out of the closet” to testify against him.

“The diplomat is still alive. The diplomat doesn’t want to talk but the diplomat is still scared,” Fagan said. “I don’t blame him all these years later. The Doodler is probably still alive.”

However, Fagan said the unnamed diplomat has continued to be cooperative with the police investigating the case.

The Associated Press contributed to this report.