A 14-year-old boy who was stabbed to death after a car crashed into his moped has been named as Jayden Moody.
The child was killed in Leyton, east London, on Tuesday night in what police have described as a targeted attack.
Detectives said a car knocked the teenager off his moped, then three males got out of the vehicle and stabbed him before getting back in and driving off.
Officers found Jayden with fatal injuries after being called to a road traffic collision in Bickley Road, Leyton, Waltham Forest, shortly before 6.30pm.
Paramedics tried to save the boy but he was declared dead at 7.09pm. His next of kin have been informed.
The Metropolitan Police is looking for a black Mercedes B Class car with "extensive front damage".
Anthony Anderson, a mechanic who works near Bickley Road, said he would often give "fatherly advice" to Jayden.
He said the boy often dropped in to his garage to get his bike fixed, and described him as a "very nice guy" who had a mature attitude and seemed older than 14.
"He's somebody I really spoke to a lot, tried to get him off the street, tried to just get him to go to school," he said. "It really, really hit me when I heard last night."
Detective Chief Inspector Larry Smith said police officers were doing "everything we can" to catch those who carried out the attack.
"Everything that we have learned about this attack so far indicates it was targeted and intent on lethal force from the outset," he said.
Around a fifth of homicide victims in London last year were teenagers, most of whom were stabbing victims. The youngest victim last year was 15.
The borough of Waltham Forest, where the killing happened, is due to receive £3m over the next four years for programmes preventing gang crime and violence.
Chief Superintendent Richard Tucker said the age of the victim "beggars belief" and had "shocked and appalled" the community.
A section 60 order has been put in place in the area to allow officers to search anyone for weapons.
Locals said the area was known for crime and some felt unsafe.
Ali Yamah, who has worked opposite Bickley Road for 17 years, said drug dealing was common in the area.
"In the evening, now it's winter time, they put on masks," he said. "Sometimes we are afraid, people are afraid of this kind of behaviour."
Claire Coghill, the leader of Waltham Forest Council, described the incident as a "tragedy that will be felt right across our borough in all our communities" and appealed for witnesses to come forward.
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"There will be members of our community who know, or suspect that they know, what happened to this child," she said.
"You need to come forward; to stay silent is to support murderers."