Haunting photos of dozens of women feared to be victims of a twisted serial killer sentenced to death this week were released by police, The Sun reported Friday.

The officials appealed for help in tracking down the women amid fears they could be victims of the so-called predatory monster Rodney Alcala.

The 66-year-old was sentenced to death earlier this week after being found guilty of killing a 12-year-old girl and four other women in the 1970s.

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

There were now fears the calculating killer could be responsible for other women who disappeared in the late 1970s.

He was described in court as a "predatory monster" and "hunter" who chased down women, torturing and killing them "because he enjoyed it."

The photos emerged as detectives carried out their investigation.

Dozens of snapshots of young women were discovered at Alcala's home and in a garage.

Some photos showed women posing in remote settings similar to the location where 12-year-old victim Robin Samsoe's body was found in 1979.

Orange County district attorney Matt Murphy said: "We know that he used his camera many times in the past to gain the trust of several of his victims.

"Then we found dozens of photos of unidentified young women who posed for him.

"We'd like to locate the women in these pictures.

"Did they simply pose for a serial killer, or did they become victims of his sadistic, murderous pattern?"

All the photos were taken before Alcala was first arrested in 1979.

He was sentenced to death twice before for Samsoe's murder, 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.

He was already linked to two murders in New York state dating back to 1977.

The serial killer conducted his own defense during his six-week trial and even played an episode of '60s hit TV show The Dating Game as part of his defense.

Relatives of his five victims burst into applause after the jury returned their guilty verdict.

Read more on this report from the Sun.