A 14-year-old boy was among four people jailed on Friday for the manslaughter of a father-of-two kicked to death for his £13,000 gold Rolex watch.
Steven McMyler, 34, was attacked in the grounds of Wigan parish church in the early evening of 6 August last year.
Manchester Crown Court heard the 14-year-old, who cannot be named for legal reasons, struck his defenceless victim over the head with a bottle as the group demanded cash.
The court heard that the boy was one of three people recruited by Lewis Peake, 30, and Michael Wilson, 20, to carry out the ‘cowardly’ attack.
McMyler was left unconscious and would have died in a matter of minutes from the impact, the trial was told.
Despite efforts from a pair of passing teenagers who performed CPR, and the efforts of paramedics who arrived on the scene, he could not be saved.
A murder probe - codenamed Operation Manhattan - was launched by Greater Manchester Police and five suspects were charged with murder.
Peake, Wilson, and the two teenagers were found guilty in May of manslaughter and conspiracy to rob.
Peake was sentenced to 13 years in jail, Wilson was sentenced to nine years.
The unnamed 17-year-old boy was sentenced to eight years in jail and the 14-year-old was sentenced to six years.
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A fifth suspect is due to stand trial for murder later this year.
Speaking after the sentencing, Detective Sergeant Heidi Cullum said: "Our endeavour from day one of this investigation was to get some justice for Steven's family and friends after he was so tragically taken away from them.
"On that evening last August, Lewis Peake, Michael Wilson and the two teenage boys, embarked on what was ultimately a fatal plot to rob Steven of his watch - when what they actually ended up doing was robbing him and his loved ones of his life.
"Their cowardly actions and subsequent denial of their roles in this killing means that there is great satisfaction for the investigation team that these four are now behind bars.
"No sentence could ever be enough for Steven's family, who have been subjected to their own life sentence, and they now must prepare to relive the trauma once again for the final trial of the fifth defendant later in the year.
"They have remained admirably strong throughout this case and my thoughts, and the thoughts of all the investigation team, remain with them today."
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