Following the death of Mr O’Halloran, who was riding a mobility scooter, detectives have released images of a man they want to identify as soon as possible.

He was seen fleeing the scene armed with a knife,” according to the Metropolitan Police.

“He is clearly a dangerous individual,” said Detective Chief Inspector Jim Eastwood, who is leading the investigation. “People are advised not to approach him, but to call us immediately on 999 if they know him or have any information regarding his whereabouts.”