A teenager described as having a fascination with the Yorkshire Ripper has been convicted of the 2014 murders of two strangers in Essex.
James Fairweather, 17, was found guilty following a two-week trial.
He had admitted the manslaughter of James Attfield and Nahid Almanea in Colchester, but denied murder on grounds of diminished responsibility.
He said he was suffering from psychosis, but the court heard a psychiatrist cast doubt on the claims.
Fairweather, of Colchester, was aged 15 when he committed both murders.
Guildford Crown Court heard he had material at his home on Peter Sutcliffe, the Yorkshire Ripper, as well as on Ipswich serial killer Steve Wright and US murderer Ted Bundy.
Mr Attfield, 33, was stabbed more than 100 times. His body was found on the Riverside Path in Castle Park on 29 March.
Ms Almanea, a 31-year-old student at the University of Essex, was stabbed on the Salary Brook Trail footpath on 17 June as she walked to the Wivenhoe campus from her accommodation in Woodrow Way.
Mr Attfield's mother Julie Finch described the killer as a "monster".
"Our lives were changed forever when my kind and brave son Jim was brutally killed," she said.
"He had been through so much already, having fought hard to overcome the effects of brain damage suffered when he was struck by a car.
"At the time, we had no idea the killer was so young - a fact that makes my son's death feel all the more cruel and unnecessary."
Ms Almanea's family issued a tribute a month after her murder.
It read: "We have been left devastated by the terrible murder of Nahid.
"Publicly, Nahid was a quiet and dignified lady who chose to pursue her academic studies in order to work towards her PHD and whilst in England she made a decision that she would respect her heritage and traditions in the way that she dressed and conducted herself.
"When she was with her family, Nahid was a warm and loving person who enjoyed laughter and the company of her parents, siblings and extended family."
The court heard Fairweather, a pupil at Colchester Academy, had been bullied at school since he was 11 and his defence argued a combination of autism, paranoia and voices in his head made him kill.
He had been questioned and released by police in the weeks after the Saudi student's death as one of 70 people with a known history of knife crime to be interviewed.
He had been convicted of a knifepoint robbery at a shop in January 2014 and was sentenced to 12 months of youth supervision.
Essex County Council confirmed he was the subject of a referral order.
An Essex County Council spokesman said: "During that time he had contact with the Youth Offending Team at least once a week and complied with all actions and appointments required of him.
"A referral order does not warrant constant supervision.
"A review of the case has since been carried out and did not identify any issues or actions which could have prevented these tragic events."
When Fairweather was arrested in May 2015, he was found hiding in bushes near the same spot he had attacked his second victim.
He was wearing latex gloves and carrying a knife.
The court heard he told police he was "going to get my third victim, but there was no-one about".
Steve Worron, Assistant Chief Constable of Essex Police, said: "Fairweather admitted killing James and Nahid, but denied their murder was calculated and pre-planned.
"He then forced their families to endure the pain and grief of a trial rather than admitting he had murdered them.
"Today's verdict will never heal the pain of losing their loved ones in such horrific circumstances.
"Hopefully they now have some answers and can be reassured their killer will face a long time behind bars."
Fairweather showed no reaction as the jury delivered its unanimous verdicts after deliberating for eight hours and 33 minutes.
The judge, Mr Justice Robin Spencer QC, warned the teenager he faced a lengthy prison sentence, adding the starting point for two murders for someone under 18 was 12 years.
Fairweather was remanded in custody and is due to be sentenced at the Old Bailey in London on Friday, 29 April.