A teenager stabbed two men to death with a kitchen knife in a violent row over a caravan pitch at a travellers' site, a court has heard.
Nelson Smith was 17 when he fatally attacked Barry Street, 32, and Nathan Oakley, 18, after the older man was accused of smashing a fellow traveller's caravan window with a can of Red Bull earlier in the day, the Old Bailey heard.
Smith's trial was told that, after the energy drink incident on December 8 last year, some residents at the council-run West Meadows site in Ipswich, Suffolk, had complained that Street was a "bully" and asked management to kick him out.
The jury heard that Stan Smith, 19, whose window was smashed, was due to move into the pitch next to Street, who habitually used it as a car park for his vehicles.
Minutes before the double stabbing, Street's female partner and the female partner of Nelson Smith's father had fought as what started as a verbal confrontation over the incident spilled over into violence, the jury was told.
Both men suffered multiple wounds, the jury was told.
Karim Khalil QC, prosecuting, said Street's partner told police she saw Smith stab him in the back close to the Bury Road site's entrance as he ran away.
A post-mortem examination revealed wounds to his neck and back.
Witnesses had also claimed the defendant said "I done it", as people crowded around Oakley after he was stabbed, the lawyer said.
Mr Khalil said: "We expect it to be suggested on the defendant's behalf that when he stabbed these men, he was defending one or more members of his family and only did what was necessary in the circumstances.
"If that account (from Street's partner) is accurate, you might find it difficult to accept that stabbing someone in the back while they are running away is a stabbing done in reasonable self-defence."
The two men were taken to hospital, one by ambulance and one in a private car, but were pronounced dead shortly afterwards.
Smith was arrested as he ran from the travellers' site, the jury was told.
Smith, who is now 18, denies two counts of murder and one of possession of a bladed weapon.
Smith, who sat in the dock wearing a grey sweatshirt, did not comment when questioned by detectives after his arrest, the court heard.
Keren Wright, who managed the traveller site for Norfolk and Suffolk County Councils, said Barry Street had been given a warning for "bullying" six months earlier, but there had been no more recent complaints until the day he died.
Plot 25, the one Stan Smith was due to take over, had a high turnover and a "pattern" of vandalism before new tenants moved in, she said.
That morning, she said, she spoke to a group of women who said Mr Street "needs to be evicted from the site, he's a bully" after the Red Bull incident.
She also learned that an older traveller, Sant Buckley, had "called him out" over the incident - a phrase used by travellers to mean he wanted to fight.
Mr Street had rejected the attempt, Mrs Wright said, because Buckley was around 60 and he did not want to fight an older man.
When she later spoke to Mr Street he denied involvement in the Red Bull incident, saying: "How could it be (me)? I was in your office with you."
Mrs Wright was off the site for 25 minutes at a meeting with a police support officer when the deaths happened, and rushed back when she saw police cars with light flashing, she said.
The trial, which is due to last three weeks, continues.