A gang member who stabbed a store manager to death during a botched raid was given a life sentence today.
Kobina Essel, 19, of east London, was told he would have to serve a minimum of 20 years for murder.
Jamie Simpson, 33, was stabbed in the neck with a 10in kitchen knife during the hold-up at a Matalan store in Hackney, east London, in March 2008.
Knifeman Essel - known as "Aggro" - was found guilty of murder by an Old Bailey jury last month.
He was also given 11 years concurrent detention for conspiracy to rob.
Judge Martin Stephens said: "This case demonstrates in a vivid way the horrors of knife crime and the terrible consequences to the victim, his family and friends and to society as a whole."
He told Essel: "You went into this with your eyes open. You went in with a knife and you did not hesitate to use it."
Essel's accomplices, Anthony Maina, 20, of Canning Town, and Randy Osei-Owusu, 17, of Poplar, as well as robbery organiser Simeon Jumah, 25, of Manor Park, all east London, were convicted of manslaughter.
The robbers had planned to steal between £20,000 and £30,000 in weekend takings from the store but fled empty-handed after the killing.
It emerged after the trial that, at the time of the raid, Maina had been on police bail for the fatal stabbing of a teenager during a mobile phone robbery five months earlier.
He was later convicted of the murder of 17-year-old Rizwan Darbar and jailed for life with a minimum term of 14 years.
Today, Maina was given indeterminate sentences for public protection with minimum terms of six years for manslaughter and five years for the robbery.
The judge said these would be served concurrently with the life sentence because he did not have the powers to make the terms consecutive.
Judge Stephens said Maina posed a significant risk of serious harm to members of the public.
Three other men were found guilty of conspiracy to rob the Matalan store.
Roy Williams, 31, of Edmonton, a friend of Mr Simpson and a security guard, was the gang's "inside man". He was jailed for ten years.
The judge told him: "Your involvement was even more despicable because you were in breach of trust."
Jammal Chambers, 18, of Poplar, recruited some of its members. He was ordered to be detained for seven years.
Duane Owusu, 20, of Manor Park, was the getaway driver. He was given eight years detention.
Aftab Jafferjee QC, prosecuting, told the trial: "Jamie Simpson had been entrusted by the store to look after the takings and he did so with his life."
Mr Simpson, from Derby, was described as "a caring, loving person, an honest, decent person" by his mother Lorna, 54, who sat through the trial with husband Lambert, 57.
She said after the verdicts: "If you talk to anybody who knows him, they haven't got a bad word to say about him."