A 13-year-old boy who admitted stabbing a man to death has been locked up for at least 11 years.
The boy, who cannot be named for legal reasons, pleaded guilty to murdering 53-year-old Christopher Barry outside his home in Edmonton, north London, on 14 December.
The mother of the boy wept in court as he was sentenced at the Old Bailey.
The court heard the boy had left a 13th birthday party with a group of friends to see another boy on to a bus as he had to head home in time for an 8pm curfew.
But on the their way back to the party, they went to the wrong block of flats and came across Mr Barry, who was outside the building with his girlfriend Sabrina Finn.
Mr Barry refused to let the three boys into the flats, the court heard.
There was "pushing and shoving" between Mr Barry and the group, before the defendant managed to get in.
He followed Mr Barry into the lift where he produced a kitchen knife from his rucksack and said: "What you saying now? What you saying now?"
The boy then stabbed Mr Barry twice, the court was told.
Mr Barry did not know straightaway that he was hurt and only realised when he took off his wax jacket when he got inside his flat and noticed blood on his shirt, Zoe Johnson QC said.
A short time later, he collapsed in a pool of blood and went into cardiac arrest, she said.
He died shortly afterwards.
After the attack, the boy told one friend that he was going to prison and texted another: "OK, if anyone asks, I wasn't there today".
He had been a member of the Wood Green gang since he was 10 years old, the court heard.
He was excluded from a school after receiving a police warning for carrying a knife on its premises.
