He had been caught in school with a knife when he was 12 and Mr Markham believed the boy, then 14, and his friends had broken into the shed at the back of his flat in Old Church Road, where he kept his tools.
On August 9 last year the boy and four friends were setting off fireworks outside Mr Markham’s home, even though he had been banned from the area by the courts.
The teenager had goaded Mr Markham to come out and stop him, telling a passer-by: “He’s going to get it. Running his mouth, he’s a c—.”
Mr Markham snapped and came out of his shed at the back of his flat brandishing a large drill bit.
The stonemason, who was just 5ft 5in and weighed only eight stone, was seen waving it above his head at the 5ft 11in teenager, who then pulled out a 18 inch knife.
His killer was well-known as a troublemaker and had wrecked the local branch of Morrisons by hurling red wine and eggs down the aisles.
He was caught on video spitting in his mother’s face and breached a criminal behaviour order five times by being in the area where he killed Mr Markham.
He has appeared in court 12 times and been convicted for 22 different offences since June 2020, when he was 13.
His previous convictions include battery, criminal damage, using threatening, abusive words and behaviour, sending threatening messages and theft
The judge said that the teenager took a knife to school, had a knife concealed in the headboard of his bed, had social media images of knives and made internet searches for buying knives.
“You regularly went missing. You had a low attendance record at school. Your foster parents could not prevent your bad behaviour. You were out of control.
Teenager was 'out of control' when he murdered father-of-three Jamie Markham, 45, outside his Chingford home
www.telegraph.co.uk