Photos of young faces -- most are of pretty women or children, some unaware they're being photographed. Others pose for the camera. Still others appear unconscious.
More than 100 people so far unidentified, captured on film by Alcala before his arrest in 1979 for the kidnapping and murder of Robin Samsoe, the 12-year-old Huntington Beach girl who disappeared on her way to ballet class.
"He was seen taking photos of her minutes before she disappeared," said Orange County District Attorney Spokesperson Farrah Emami.
Prosecutors say Alcala, a freelance photographer, approached some of his victims and asked to them to pose for photos to get them to lower their guard. To view the series of photographs, click here.
Alcala, 66, listened to applause as jurors recommended he receive a death sentence for what he did to Samsoe and four other women from Los Angeles County in the 19700s.
Alcala tortured, sexually assaulted and murdered 18-year-old Jill Barcomb, 27-year-old Georgia Wixted, 32-year-old Charlotte Lamb and 21-year-old Jill Parenteau.
Alcala also posed Parenteau's body.
"We now are concerned that there are other women out there who may have cold cases that are unsolved, that some of these people may have been sexually assaulted," said Farrah.
Authorities discovered the unidentified photos in Alcala's rented storage locker in Seattle. In some photos the women are nude. Some pictures were taken in remote settings.
"Just let us know who they are so that we can confirm that they're safe or we can give some closure to a victim's family who's been waiting for a really long time," said Farrah.
If you recognize anyone in any of the photos, you're asked to call the Huntington Beach Police Department at (714) 536-5947.
To view the series of photographs, click here.