Images of women that police are seeking the public's help in identifying are seen in a selection of photographs found in the possession of the serial murder suspect dubbed the 'Grim Sleeper'. Photograph: Reuters

The Los Angeles police were deluged with calls today in response to their grim release of pictures of 160 women, some feared to be possible victims of the Grim Sleeper serial killer.

The photographs, dating back to the 1980s, are alleged by police to have been found at the home of Lonnie David Franklin, who was arrested in Los Angeles in July and charged with the murder of 10 women. Franklin denies he killed them.

The detective leading the investigation, Dennis Kilcoyne, said yesterday he expected the department to field 1,000 calls by the end of the day.

The police said that, as a result of the calls, they could tentatively identify about five of the 160, but they did not say whether the women were alive.

The photographs were posted by police online in an attempt to establish whether the women are still alive or if they had been murdered too. If the women are alive, police hope they can be found or that they would come forward and help to fill in gaps in the knowledge about Franklin.

The police published 180 photographs, some of which show the same women but in different poses.

The suspect being held is thought to be the Southside Slayer, a serial killer's moniker from the 1980s, which later became the Grim Sleeper because of an apparent 14-year lull between murder sprees. Police have admitted that they do not know for sure whether the killings actually stopped during the lull, between 1988 and 2002.

The Los Angeles police department said that while officers agonised over whether to publish the online photo gallery, concerned about the embarrassment it might cause to women still alive, they wanted to know who they are. "We are grateful for the public's response to the release of the images," said a police statement. "It is our fervent hope that with this response, coupled with the tireless efforts of our detectives, the women depicted in these images will be positively identified."

In the pictures, most of the women were either partly or completely naked but the police cropped them so that only their heads and shoulders are visible online. Officers said they were very concerned for those in the photographs.

Franklin, 57, a retired car mechanic, has pleaded not guilty to the 10 murders, committed between 1985 and 1988 and from 2002 to 2007. Some of the victims were prostitutes. The killer shot some women and strangled others.

The photographs were alleged to have been found in Franklin's house, cars and garage, with some lying around and others apparently hidden. The ages of the women in the photographs range from teenage to 60-plus and almost all are black, apart from a handful. In many, the women are smiling, and police suggest they were not being coerced, at least at that point. A few show women with their eyes closed: they may not have wanted to be identified, or could be asleep or dead.

Some of the pictures were from video film, some from digital cameras and some from unexposed film. The police said they only took the decision to release the photographs after months of trying to establish the identities of the women. "We certainly do not believe that we are so lucky, or so good, as to know all of his victims," said Charlie Beck, the police chief, on Thursday. "We need the public's help."

Police said they found Franklin allegedly through DNA evidence linking him to the murders. A preliminary hearing in the case is set for 31 January.