A story found on the accused Claremont serial killer's electronic devices has striking similarities to a graveyard rape he allegedly committed, a Perth court has heard.
Bradley Robert Edwards, 50, is charged with murdering Ciara Glennon, 27, Jane Rimmer, 23, and 18-year-old Sarah Spiers between 1996 and 1997.
He is also accused of attacking an 18-year-old woman in her family's Huntingdale home in 1988, when he was 19, and twice raping a woman abducted from Claremont and driven to Karrakatta cemetery in 1995.
Edwards cannot explain his DNA on the cemetery victim, a kimono found at the Huntingdale property or Ms Glennon's fingernails, and the defence team is still deciding whether to challenge this evidence.
In a pre-trial hearing on Wednesday, the WA Supreme Court heard details about Edwards' alleged depraved obsessions, with prosecutor Carmel Barbagallo saying "Chloe's Story" was "strikingly similar" to the Karrakatta offences.
It involved meticulous planning before a "blitz attack", fabric in the victim's mouth, handcuffs, a hood and driving the victim around.
"It can't be coincidental that a man who is forensically linked with rape, abduction, murder, with hoods and handcuffs, is subsequently found to have an obsessive interest in that sort of matter."
Ms Barbagallo said there was a theme in stories found on Edwards' devices, with some involving abductions and sexual assaults "often with the implication that the woman won't be leaving".
Some women were incapacitated and pleaded for their attacker to stop.
One story evolved with at least 28 amendments between December 2015 and December 2016, when Edwards was arrested.
An issue is whether he authored, contributed or just accessed the stories.
"What is the chance of finding this material ... that identifies this obsessive reference to the behaviour, the kind of conduct that he is ultimately charged with?" Ms Barbagallo said.
Justice Stephen Hall said presumably more people had an interest in such behaviour than committed actual rapes.
While the Karrakatta allegations and Chloe's Story had similarities, some features were generic, defence counsel Paul Yovich argued.
The court heard the twice-married Edwards, who was previously convicted of assaulting a woman he tried to drag into a hospital toilet, also compiled a list of 3942 pornographic website addresses, including some containing extreme BDSM material.
Ms Barbagallo said there was a correlation between turmoil in Edwards' personal life and the alleged offending, but it was not causative.
"(As) his relationships become more tumultuous ... the escalation in violence follows that path," she said.
"All of the murders of the girls ... are committed at a time when he is on his own."
But Mr Yovich suggested "the emotional upset factor" was a coincidence.
"No person is going to be on an emotionally even keel all the time."
Mr Yovich also argued the two Huntingdale offences should be heard separately to the murders and Karrakatta cemetery offences.
Justice Hall has reserved his decision on that and whether the prosecution's propensity evidence will be admissible in a nine-month trial without a jury starting in July.
Australian Associated Press