Investigators said Tuesday they are trying to find at least 50 women they have linked to a photographer on death row for murdering two aspiring models in the early 1980s.

Authorities are looking into whether the women were raped or killed between 1975 and 1984 by William Richard Bradford, according to a Los Angeles County Sheriff's Department Web site.

In the 1970s and '80s, Bradford posed as a freelance photographer in the West Los Angeles area, taking sexually explicit photos of women he met at bars and auto races, according to the site. The site showed women striking poses in 54 photographs seized from his home in the 1980s.

Investigators renewed their interest in the photos while reviewing old cases recently, but they have had trouble contacting the women, said sheriff's Lt. Debra Lenhart. She said the case has generated leads in Michigan and Florida. Bradford, now 60, once lived or traveled there.

Bradford was convicted in 1987 of murder in the stranglings of Shari Miller, 21, and Tracey Campbell, 15. Prosecutors said he lured them by promising to help with their modeling careers. The victims' bodies were found during the summer of 1984, one of them in a Los Angeles parking lot, the other in the desert north of the city.

In the penalty phase of his trial, Bradford asked the jury to sentence him to death.

"Think of how many you don't even know about," he told the jurors.

It was not unclear whether Bradford has an attorney. A message left with an attorney who represented him in the past, Robert R. Bryan, was not immediately returned.

The unaccounted-for women were believed to have lived in West Los Angeles, Santa Monica, Culver City, Inglewood and other beach cities.

Shortly after his arrest in the two killings in 1984, he pleaded no contest to an unrelated charge of rape and was sentenced to eight years in prison.