The teenager who threw a six-year-old boy from the viewing platform of the Tate Modern gallery in London told of plans to push someone off a high building a year earlier, it has been reported.
Jonty Bravery, 18, admitted pushing the French child from the tourist attraction's tenth floor on August 4 last year.
A recording from autumn 2018, obtained following a joint investigation by BBC News and the Daily Mail, allegedly reveals him telling his carers of a plan to kill someone.
The audio, reported to be the voice of Bravery, says: "In the next few months I've got it in my head I've got to kill somebody."
Bravery, who is autistic, also allegedly tells his carers he wants to go into central London and visit a tall landmark to push somebody off it.
Care provider Spencer & Arlington told the BBC they had "no knowledge or records of the disclosure".
In a statement, it said there was "absolutely no evidence" that Bravery "may have told his carers of his plan".
Spencer & Arlington said that there was no record of the disclosure in any care plan, care report or review from managers or his carers, psychologists, or health workers.
But the company said it recognised the "gravity" of the claim and has reported the concerns to the Care Quality Commission (CQC).
Bravery, of Ealing in west London, admitted a charge of attempted murder in December at the Old Bailey in London and is due to be sentenced in February.
The court previously heard how Bravery was seen wandering about the viewing platform before picking up his victim and throwing him over the edge.
The six-year-old boy, who cannot be named for legal reasons, suffered a bleed to the brain, fractures to his spine and broken legs and arms following the fall.
The boy was visiting London with his family at the time and is now said to be recovering in his native France.
A GoFundMe page set up to raise money for the six-year-old's intensive rehabilitation said that he had started to speak again shortly before Christmas.