Dominic Barritt was attacked outside a shop in Walton in Essex
A violent man has admitted killing a trainee bricklayer who he punched to the ground in Essex.
Mark Brewer, 22, of Walthamstow, east London, punched 18-year-old Dominic Barritt as he walked near his home in Walton-on-the-Naze.
Mr Barritt died after he hit his head on the ground in the attack on 23 August, Chelmsford Crown Court heard.
Brewer, who has a history of violence, is due to be sentenced in February. He was remanded in custody.
Judge Christopher Ball QC adjourned sentencing until the week starting 9 February to allow background reports to be prepared.
He said Brewer had a lengthy criminal record and could be "a significant danger."
"His history is extensive and involves offences that entail the use of violence, possession of weapons and the taking of drugs," he said.
"He is someone who may for some time to come represent a very significant danger."
Gareth Hughes, prosecuting, said Mr Barritt hit the back of his head after being punched to the floor.
"He met his death following a single punch," said Mr Hughes.
"He went straight to the ground, hitting the back of his head, and really never recovered."
Brewer denied murder and the judge said a jury would have found it "almost impossible" to conclude that he intended to cause grievous bodily harm or intended to kill.
At an earlier court hearing magistrates were told that Brewer had become involved in a row with a girl Mr Barritt was walking with.
Brewer was remanded in custody.