Seventeen year-old Bienda Litambola was kicked and beaten to death in a row over a text message.
Bienda had discovered that the 18 year-old girl was being contacted by her ex Larry Morrison, a 22 year-old heroin dealer.
He reacted by texting Morrison saying: 'Stop taking the piss and phoning up my girl.'
It was this message that led to the fatal confrontation on November 17, 2007.
After receiving threats, Bienda drove to Larry Morrison's flat in Munday Road, Canning Town, east London.
Minutes after his arrival he was attacked by both Larry Morrison and his younger brother Michael Morrison, 21.
Peter Clarke, QC, prosecuting, said: 'Both men were seen to hit Mr Litambola then kick him when he was down around the upper body and head area and one of them used a dog chain that was wrapped around in a loop as a baton.
'He was seen by one witness to try to hold one of the men to stop being kicked. He also tried to grab the dog chain.
'The men continued to attack him even after he was obviously losing consciousness.'
Bienda - a Congolese National known as Bob - died after his heart stopped during the attack. He was then left in the road as the Morrison brothers told him: "That's what you get - you deserve it."
During their trial at the Old Bailey in June 2008 the pair admitted manslaughter but claimed the victim threw the first punch.
The case was almost halted after three members of the jury panel reported being intimidated by people from the public gallery as they made their way home from court.
They said they were stopped on an escalator at St Paul's underground station and told: 'Hope you can sleep at night.'
But the trial continued after the jury said the incident would have no bearing on their verdict.
They convicted both Morrison brothers of murder by a majority of ten to two.
Judge Richard Hawkins QC sentenced both men to life imprisonment with a minimum of 12 years behind bars.
He said: 'Bob was a young man, only 17 years old, a teenager on the verge of his adult life. You were older and much more mature.
'He sent a text to you Larry. He was jealous of you and told you to stop contacting his girlfriend.
'Like I said you were older and more mature and should have dealt with it in another way.
'On the day of his death it was he who came round to you but the two of you made a concerted attack on him, both punching him and there was a dog chain.
'It was undoubtedly used deliberately and you got him to the ground and kicked him.
'His apparent injuries were minor and the death was a tragedy and totally unexpected.
'Bobby was a teenager on the verge of his adult life. You were older and more mature and should have dealt with it another way.'
After the trial the victim's sister Tyeisha paid tribute to her 'ambitious and intellectual' younger brother.
'Seeing him in a morgue and seeing him at the funeral home, nothing prepares you for that,' she told the court.
'Bob was quiet. With his friends, if there was any animosity between friends or any person he would be the one to stop it rather than start it.
'He wasn't a violent person, not at all. The family doesn't want retribution, we merely want justice.'
Only seven months before his death, Bob spoke to the BBC about fear of crime in Newham, east London.
Memorial page for Bienda Litambola on gonetoosoon.org