Prosecutors said convicted serial killer Rodney Alcala used his camera to gain the trust of young women and now they fear photographs he snapped decades ago could contain images of more potential victims.

Hundreds of Alcala's photographs, apparently taken before his first arrest in 1979, were released by Huntington Beach police Wednesday, featuring women and girls in candid and posed shots. Some show them naked and engaging in sex acts.

Most of the dozens of subjects in the photos have never been identified and now police are asking for the public's help in figuring out who the women are.

A jury recommended death Tuesday for Alcala, 66, in the murders of a 12-year-old girl and four women dating back to the seventies

Prosecutors said Alcala, an amateur photographer and UCLA graduate, used his camera to put his victims at ease.

"We'd like to locate the women in these pictures," prosecutor Matt Murphy told the Orange County Register. "Did they simply pose for a serial killer, or did they become victims of his sadistic, murderous pattern?"

Detectives recovered hundreds of photos during court-authorized searches of Alcala's Monterey Park home and a rented storage locker.

Some photos show women posing in remote settings similar to the locale where 12-year-old Robin Samsoe's body was found in 1979. A few are of young men in sexually suggestive poses.

Jurors took just an hour to return the death recommendation after a six-week trial in which Alcala represented himself and took the stand in his own defense.

Alcala was sentenced to death twice before in the 1979 murder of Robin Samsoe, but those verdicts were overturned on appeal.

Prosecutors refiled charges in that case and added the four other murders in 2006 after investigators linked them to Alcala using DNA samples and other forensic evidence. Those cases, which had gone unsolved for decades, went on trial for the first time this year.

Alcala focused his entire defense on the Samsoe case and ignored the murders of the four Los Angeles County women murdered between 1977 and 1979.