Kevin Hutchinson-Foster was today found guilty at the Old Bailey of supplying a gun to Mark Duggan, whose fatal shooting by police sparked riots in London.
A jury at Snaresbrook Crown Court could not reach a verdict after a trial last year, but after a retrial, a jury of seven women and five men today convicted him by majority verdict.
Hutchinson-Foster, 30, had denied a charge of "selling or transferring a prohibited firearm" to Mr Duggan between July 28 and August 5, 2011.
During both trials armed police, who gave evidence anonymously, described how they opened fire on Mr Duggan because they saw him get out of the cab holding a loaded gun.
Mr Duggan, who was under police surveillance the day and the day before, had gone in the minicab to Leyton, east London, where he collected the gun in a shoebox from Hutchinson-Foster, before continuing to Tottenham.
The cab was pulled over by armed police in four unmarked cars in a "hard stop", and as Mr Duggan got out clutching the gun, he was shot.
The officer who shot Mr Duggan twice - once in the chest and once in the arm - said he fired because he thought he was going to shoot him and his colleagues.
During the trial, prosecutor Edward Brown QC told the court: "The death of Mr Duggan has been regarded as the event that sparked the riots in north London, which then spread across London and then to other cities and which attracted widespread publicity in the United Kingdom and abroad."
He told the jury it was not their task to decide the "rights and wrongs" of Mr Duggan's shooting, which will be examined at the inquest into his death, set to take place in September.
However Mr Duggan's family have spoken of the "deep sense of injustice" over the accounts of his death that emerged during Hutchinson-Foster's trial, and their frustration at continued delays of his long-awaited inquest.
Mr Duggan's mother Pamela has said it was "heartbreaking" that she will have endured a wait of more than two years for the inquest into her son's death, which is now not expected to begin until September.
From the start of Hutchinson-Foster's original trial in September, Mr Duggan's family have remained adamant that the question of whether he was holding a gun is something that should only be addressed at his inquest.
Speaking after a pre-inquest hearing, she said: "It's heartbreaking for me, he's my son. It's taken me a lot of courage to come here today. He was only 29 and he was killed and he's got children."
Mr Duggan's family have previously have criticised what they call the prosecution's "unjustified and untested" claims in Hutchinson-Foster's trial.
Hutchinson-Foster has admitted using the same gun to beat barber Peter Osadebay at a barber's shop in Dalston, east London, just six days before Mr Duggan's death.
The defendant claimed this was why his DNA was found on the gun when it was retrieved from Ferry Lane on August 4, along with traces of Mr Osadebay's blood.
The gun was found five metres from Mr Duggan's body, on a grass verge behind railings.
The shoebox, found in the minicab, had both Mr Duggan's and the defendant's fingerprints on it, while mobile phone evidence showed they were in contact with each other in the run up to the shooting.
But Hutchinson-Foster, a cannabis user with convictions for possession of cocaine and heroin with intent to supply, claimed Mr Duggan had wanted his help to sell some cannabis.
He said he collected the firearm from someone else so he could beat Mr Osadebay on July 29, but had returned it on the same day.
The jury heard testimonies from the CO19 officers who shot Mr Duggan.
The man who opened fire on the 29-year-old, known only as V53, said he was sure Mr Duggan was holding a handgun.
He shot Mr Duggan once in the chest, then a second time, hitting his right bicep. Afterwards he went to treat a fellow officer who had been hit by a stray bullet, but realising it had hit his radio, started giving CPR to Mr Duggan.
Other officers told the court Mr Duggan was hiding something in his hand when the cab was stopped and saw him raise what appeared to be a gun as he got out.
But the minicab driver, who said he would never be able to wipe the incident from his mind, said he did not see Mr Duggan raise his arms towards officers.
After the verdict, the jury was shown CCTV of the incident at the barber's shop on July 29, 2011, where Hutchinson-Foster threatened Peter Osadebay, then returned and used the gun to beat him.
The court heard that Hutchinson-Foster is in prison serving a 54-month sentence for possession of cocaine and heroin with intent to supply. That sentence is due to finish in December.
He had been released from prison after a previous sentence in April 2011, and committed these offences while on licence, Mr Brown said.
The case was adjourned until 11am on February 26, when Hutchinson-Foster will be sentenced.
Alison Saunders, CPS London chief crown prosecutor, said: "The CPS proceeded with this prosecution based on evidence that Kevin Hutchinson-Foster had transferred a gun to Mark Duggan hidden in a shoe box in Tottenham on 4 August 2011.
"He had already lied about possessing the same gun and beating a person with it six days earlier, despite strong evidence linking him to that offence.
"He eventually pleaded guilty to those charges and today a jury found him guilty of this further offence.
"We are committed to tackling the menace of gun crime and will continue working closely with the police to pursue and prosecute those who supply or transfer the weapons that have caused terrible pain to so many families.
"This conviction sends a strong message that gun crime and violence will not be tolerated in London."