San Francisco police have renewed their appeal to identify “The Doodler,” a serial killer who targeted gay men more than 50 years ago, offering a $250,000 reward for information.

Investigators believe the killer murdered six gay men between January 1974 and June 1975.

Police say the victims were all targeted because they were gay, and that each met the suspect shortly before being killed in isolated coastal locations.

Four bodies were found around Ocean Beach, with another in Golden Gate Park.

The victims were 49-year-old Gerald Cavanaugh, 27-year-old drag and comedy performer Joseph “Jae” Stevens, 31-year-old Klaus Achim Christmann, 52-year-old lawyer Warren Andrews, 32-year-old nurse Frederick Elmer Capin and 66-year-old Harald Gullberg.

The killer was dubbed “The Doodler” because a surviving victim said he had described himself as a cartoonist and was sketching during their conversation at a late-night diner.

Police say he typically met men at after-hours bars and restaurants, sketched them, and lured them to secluded spots before attacking.

He was described as a clean-shaven African-American man, around 5’11” and in his early 20s at the time, meaning he would now be in his mid-70s.

Police have identified a person of interest who is still alive and living in the Bay Area, and are reportedly working with the FBI to compare the killings with others nationwide.