Police in San Francisco on Wednesday released a new sketch in the decades-old case of a suspected serial killer who targeted gay men in the 1970s and announced a $100,000 reward for anyone who can provide information leading to the identification of the suspect.

The sketch depicts what the suspect may look like today.

The suspect was dubbed "the doodler" after he told a man, who became a victim but survived, that he was a cartoonist, police said at a news conference Wednesday. That victim told police that the suspect was drawing caricatures on a paper while the two spoke in an all-night truck stop diner, Greg McEachern, San Francisco Police Department Commander of Investigations Bureau, said Wednesday at a news conference.

He is suspected in at least five homicides of gay, white men between January 1974 and June 1975, Greg McEachern, San Francisco Police Department Commander of Investigations Bureau, said Wednesday at a news conference.

"What made investigators at the time believe that all of those victims were as a result of the same suspect was that they had similar injuries, including stab wounds to the upper chest and back," McEachern said.

DNA evidence "from a couple of homicides" has been submitted and is being tested, police said.

San Francisco police released a new sketch Wednesday showing what a serial killer who targeted gay men in the 1970s could look like now in hopes of getting a break in the cold case. San Francisco Police Department

The suspect met his targets at gay clubs and restaurants in the city, police said, and he often had sex with them before attacking them, according to NBC Bay Area.

The bodies of four victims were found on Ocean Beach, a fifth at Golden Gate Park.

"Connections between the doodler attacks and the five homicides led investigators in the San Francisco Police Department's Homicide and Cold Case Unit to believe the same suspect is responsible for both sets of crimes," police said in a news release.

Police on Wednesday also released an audio recording from a Jan. 27, 1974, call from an unidentified person to police dispatch reporting a man's body on Ocean Beach.

The caller refused to identify themselves to the dispatcher, police said.

A suspect was detained in 1976, but was never charged, police said Wednesday. They believe that a psychiatrist with the last name Priest may have been treating the person of interest that was identified in 1976, McEachern said.

Two white men survived assaults in July 1975 that occurred two weeks apart at the same residence in San Francisco, police said. One of those victims was stabbed with a knife and sustained injuries similar to the homicide victims the previous year, police said.

Both of the victims who survived the July 1975 assaults gave police similar descriptions of the suspect.

"After recovering from one of those injuries, one of the victims was able to provide investigators with more information, and it's what led investigators to believe that the suspect in those two assaults may also be the suspect in the homicide," McEachern said.

Police released an age-progression sketch that depicts what the suspect may look like today.