Police failed to submit a laptop belonging to serial killer Stephen Port for forensic analysis for 10 months after it was seized, and then missed repeated searches for drug rape videos contained on the device, an inquest has heard.
Port killed four men with overdoses of the drug GHB between June 2014 and September 2015.
Inquests into their deaths are looking at whether lives could have been saved had police acted differently.
Anthony Walgate, 23, Gabriel Kovari, 22, Daniel Whitworth, 21, and Jack Taylor, 25, were all found dead near Port’s flat in Barking, east London.
Fashion student Mr Walgate, who was working as an escort, died after agreeing an overnight visit with Port for £800.
Port initially lied and pretended not to know who Mr Walgate was, and was arrested for perverting the course of justice on June 27, 2014.
The inquests into the four men’s deaths, being held at Barking Town Hall, heard on Wednesday that homicide investigators had advised detectives in a local borough policing team to analyse Port’s laptop, on the day of his arrest.
But the analysis was not carried out and it was only in April the following year, 10 months later, that the machine was sent to a forensic scientist.
Then two months later, in June 2015, Detective Constable David Parish was provided with a USB stick containing all the material from Port’s computer.
This included repeated searches for drug rape videos and date rape drugs, just before Port messaged Mr Walgate proposing the overnight visit.
In another message on the FitLads site, before he met Mr Walgate, Port bragged about previously having had sex with a man who was on drugs and was like “a ragdoll”.
But Mr Parish did not spot the material and reported only on selfies, sex videos and dating site messages on the laptop.
Giving evidence on Wednesday, he told jurors that he did not go through Port’s internet searches around the time of Mr Walgate’s death.
He said: “That was something that I didn’t do and I should have done and I apologise.”
The officer said he was looking for information about how Port and Mr Walgate met, and their lifestyles.
While Port was on bail, having been arrested for perverting the course of justice, he murdered Mr Kovari, who was found dead on August 28 2014, and Mr Whitworth, who was discovered on September 28 that year.
Earlier, university friends of Mr Walgate told the jury that they had been convinced that their friend’s death was suspicious, and feared that police wrongly assumed he had overdosed on drugs because he was working as an escort.
Giving evidence via videolink from Hong Kong, where she lives, China Dunning told the inquests: “I was convinced that Anthony’s death was suspicious. I just knew that he hadn’t taken drugs himself and overdosed.
“I was convinced that it was the actions of Stephen Port. I was convinced that he had his drink spiked or something, and that it was suspicious.”
Kiera Brennan, who was part of the same circle of friends, also told the inquests that she “felt strongly” that Port had caused Mr Walgate harm.
Mr Walgate would sporadically work as an escort and had arranged to meet Port, who was using the false name Joe Dean, on June 17 2014 at his flat in Barking.
Miss Dunning reported Mr Walgate missing two days later, along with the name, address and date of birth that Port had provided and a physical description of him.
In September 2014, as the investigation into Mr Walgate’s death continued, Miss Dunning told police that if toxicology reports found GHB in his body she did not believe he would have taken it of his own accord.
Asked about the way the police responded to her concerns that her friend’s death may be suspicious, Miss Dunning said: “They received the information professionally but I was also aware that maybe they might have come to the assumption that he was young, gay, a sex worker, and I just thought that they would instantly assume ‘yes, he does drugs as well’, or he would be willing to, or he would take the risk.
“I wanted to convince them that they shouldn’t have that stereotype.”
The court was read parts of an earlier statement in which Miss Brennan said the police saw Mr Walgate as “a young boy shagging people for money” and that “when they found out he was an escort they wrote him off”.
She told the inquest: “I don’t think it was actively against gay people.
“But I do think there was an unconscious bias and assumptions made because of Anthony’s sexuality, because of the job that Anthony was doing.
“I definitely think that had an impact on how things were conducted or not conducted.”