In the hours and days after the shooting of Rhys Jones, local residents spread the word that Sean Mercer was the gunman.
Despite this common knowledge, many people remained too frightened of the gangs to speak out about what they knew and it took "inspired" and controversial detective methods to bring him before the jury at Liverpool Crown Court.
Merseyside Police placed bugging devices in the homes of Yates and McCormick.
Months later, detectives took the decision to offer immunity from prosecution to Boy X, 17, who Mercer called upon to hide the gun.
Together with information from cell sites - mobile phone telemasts which can be used pinpoint the location of a phone user - the police were able to piece together the movements of Mercer and his cohorts.
Much of the information obtained by the bugging devices cannot be reported for legal reasons.
A source within one of the defence teams said: "The power of the probes was that they were placed very soon after the murder in exactly the right homes, although for all I know the homes of all the defendants might have been bugged.
"The difficulty with bugs in those situations is establishing the context of the speaker - people might be gossiping, or drunk or just making things up.
"But it was an inspired move because it provided a crucial piece of the jigsaw - telling them who did what and when."
Boy X had been a suspect for several months before he was offered immunity in November last year.
Police raided his home a month after Rhys was shot and the boy, who was on holiday in Florida, was arrested on the apron of Manchester Airport some days later.
He told police how he had been summoned by Mercer to the home of Boy M where he was handed the gun to hide and told: "Don't say nothing to no one."
Helen Morris, the chief prosecutor for the Crown Prosecution Service, said she didn't go down the track of giving Boy X immunity lightly.
It is thought to be the first time such a witness has been given immunity like this under the Serious Organised Crime and Police Act 2005.
Mrs Morris said: "Merseyside Police asked me to consider the immunity provisions as a possibility.
"There then followed weeks of inquiry to investigate the character of Boy X, the truth of what he was saying and to gather independent evidence in support of what he was saying.
"Only after this had been done were we confident to refer the matter higher up for a decision by the director of public prosecutions about the immunity agreement."Reuse content