Handout / San Francisco Police Department

San Francisco police have released an updated sketch and issued a $100,000 reward for information in the cold case search for the "Doodler," a suspected serial killer who targeted white gay men in the mid-1970s.



In a press conference Wednesday, SFPD Cmdr. Greg McEachern said that investigators believe the killer stabbed at least five men to death between Jan. 1974 and Sept. 1975.



"We’re here to ask for help so we can bring justice to the victims of these horrendous homicides that happened in the 1970s to gay white men," he said.



The suspected killer was nicknamed the "Doodler" because he would attract his victims by drawing caricatures in bars and restaurants in San Francisco's Castro District, a now-famous LGBT neighborhood that had just begun to establish itself. It's believed the killer would have sex with the men before becoming violent and killing them.



McEachern said that the original sketch of the suspect was obtained from victim interviews after police at the time linked the killer to two violent assaults in July 1975. The assault victims — both white gay men — had similar injuries to those found on the bodies of the five Doodler victims, gave similar descriptions of their attacker to police, and one of the men even said that his attacker had been drawing caricatures on a piece of paper when they met in a late-night diner.



Mickey Pfleger / The LIFE Images Collection / Getty, Harold Adler / Getty Images San Francisco in the 1970s.

Both victims described their attacker as a "black male, approximately 19-25 years old, 5'11-6'0, lanky in appearance, with a medium complexion and smooth skin," per police.



A forensic artist then took the 1975 suspect sketch created from those descriptions and used age progression imaging to create a picture of what the Doodler might look today, McEachern said.



The identification and arrest of the infamous Golden State Killer last year prompted the head of the department's cold case unit, inspector Dan Cunningham, to begin revisiting unsolved murders, particularly suspected serial murders, McEachern said.



Although detectives at the time of the murders speculated that the Doodler could have killed as many as 14 men, police have only confirmed the murders of five known victims: Gerald Cavanaugh, Joseph "Jae" Stevens, Klaus Christmann, Frederick Capin, and Harald Gullberg.



“We’ve made some progress, but this one has been frustrating,” Cunningham told the San Francisco Chronicle. “There just wasn’t as much attention back then to this case overall because it involved gay people," he said. “And some of the people involved were reluctant to come forward because of the gay aspect, and the conditions at the time."



The Associated Press / July 8, 1977.