A man who sexually assaulted two women after killing them performed similar sex acts on bodies at two hospital mortuaries, a court has heard.

David Fuller, 67, is on trial for the murder of Wendy Knell, 25, and Caroline Pierce, 20, in two separate attacks in Tunbridge Wells, Kent in 1987. He initially denied killing the women but changed his plea to manslaughter by reason of diminished responsibility after learning of DNA evidence, Maidstone crown court heard on Monday.

Knell was found dead in her apartment in Guildford Road on 23 June 1987. Her body showed signs of blunt force trauma to the head, asphyxiation to the neck, and sexual assault after her death, the court was told.

Pierce was killed five months later outside her home in Grosvenor Park on 24 November of the same year. Neighbours described hearing screams from her flat on the night in question, the court heard. She was then reported missing and there was no sign of her in her flat. Her naked body was discovered three weeks later in a water-filled dyke at St Mary in the Marsh in Kent on 15 December 1987.

There were reports of “prowler activity” in the lead-up to both their deaths, with local women reporting a voyeur looking through their windows, said the prosecutor Duncan Atkinson QC.

Fuller, an electrician, was arrested on suspicion of murder on 3 December 2020 following new analysis of decades-old DNA evidence. Officers searched his home, finding images of dead women at the two hospital mortuaries being abused by Fuller, the court heard.

Four hard drives attached to the back of a cupboard “were found to contain a library of unimaginable sexual depravity”, said Atkinson.

“There were both photographs and videos which showed the defendant sexually abusing female corpses in the mortuaries of the two hospitals at which he worked, first the Kent and Sussex hospital, where he worked full-time from 1989, and then the Tunbridge Wells hospital, to which he moved in 2010.”

In a police interview, Fuller admitted to using Facebook to search for photos of the people he abused in the mortuary, the court heard.

“He admitted to searching for them on the internet, including on Facebook,” said Atkinson. “He claimed that this would be after the offending, rather than research before offending.”

Fuller would later go back and name the files containing images of his offending against dead people using the ledgers from the mortuary and identification tags on the bodies, the court heard.

The prosecutor said these images provided evidence that Fuller committed the acts out of “sexual gratification” and not mental illness. “It shows the defendant derived sexual gratification from sexual activity with those who have died,” said Atkinson.

He added: “It therefore provides a reason for the killings, however deviant and repellent, that does not depend on an explanation of mental illness that deprived the defendant of his self-control.”

Atkinson added that there was no evidence of the defendant suffering from mental health problems until 2010, when Fuller complained of feeling depressed over pain in his legs.

The trial continues.