Rackauckas said each possible match to one of the photos is investigated first by looking at the whereabouts of the victims at the time and that of Alcala. In some cases, he said, DNA evidence is available for further confirmation.
Alcala, who had a fine arts degree from UCLA, took the photos before his first arrest in 1979.
Some show remote settings similar to the region where Samsoe's body was found. A few of the photos are of men.
Police say Alcala thought of himself as a skilled photographer and may have used the camera to lure his victims.
Alcala had traveled across the country several times when he was studying film at New York University in the 1970s, even working briefly with director Roman Polanski.
Steve Hodel, a retired detective with the Los Angeles Police Department, told ABC's Nightline that Alcala could have killed many more victims between the East and West Coasts.
If you know who these women are, contact Huntington Beach Police Detective Patrick Ellis, at 714-375-5066, or e-mail him at firstname.lastname@example.org.