A teenager has admitted killing two people who were set upon while out walking in a garrison town.
The 17-year-old, who cannot be named for legal reasons, stabbed James Attfield, 33, more than 100 times in Colchester on March 29 2014.
Mr Attfield, who had a brain injury after being hit by a car four years before his death, was found fighting for his life in the town's Castle Park. He died later in hospital.
Three months later, the boy knifed Saudi student Nahid Almanea, 31, 16 times as she walked along the Salary Brook Trail towards the University of Essex on the morning of June 17 2014.
She was wearing a Muslim gown called an abaya when she was attacked.
The two deaths sparked fears a killer was randomly striking after police said there were "striking similarities" in the murders but nothing to link the victims.
The teenager, from Colchester, was arrested after allegedly being found with a lock knife on May 26 last year in the same area where Ms Almanea was killed.
During a hearing at the Old Bailey, he denied two counts of murder and possessing an offensive weapon but admitted two alternative counts of manslaughter by reason of diminished responsibility.
Mr Justice Spencer allowed the prosecution time to consider the pleas.
A murder trial has already been fixed to start on April 11 at a venue to be decided, either in Guildford or central London.
A tearful couple, believed to be the boy's parents, sat in the well of the court and blew him a kiss as he sat flanked by officers in the dock.
The defendant, who wore a grey suit, leather jacket and black rimmed spectacles, spoke only to enter his pleas and confirm his name. He was remanded in custody.