The Supreme Court has reinstated the murder conviction of a man who took part in a shootout, even though he did not fire the fatal shot.
Armel Gnango was 18 when he was jailed for life in 2008 for the murder of care assistant Magda Pniewska in New Cross, south London, in October 2007.
She was caught in crossfire between Gnango and a man who was never caught.
The judges ruled Gnango's actions had aided and abetted the killing and the verdict had been wrongly quashed.
At his trial the Old Bailey jury was told that scientific evidence had shown it was not Gnango's weapon that fired the bullet that hit Ms Pniewska in the head as she walked home from work.
She was talking on her mobile in a car park when she was shot. Her sister Elzbieta Luby told the trial she heard Ms Pniewska's last breath down the phone.
The jury ruled Gnango was responsible for the killing because he was involved. The other man involved in the shooting was referred to in court as B.
'Astonished and appalled'
At the time the conviction for murder of someone who was known not to have fired the fatal shot in such circumstances was described by the Crown Prosecution Service (CPS) as "unprecedented".
Gnango was also given a minimum 12-year term for attempted murder and a five-year sentence for possession of a firearm, both sentences to run concurrently.
The Court of Appeal ruled that "joint enterprise" liability for murder, the basis on which the court considered his conviction to rest, could not arise on the facts.
But considering a further appeal from the Crown, the Supreme Court concluded that whether Gnango was described as a principal or an accessory to the shooting was irrelevant to his guilt.
In the judgement, the court said the all-important consideration was that both Gnango and B were intentionally engaged in a "potentially lethal unlawful gunfight".
Lord Brown said: "The general public would be astonished and appalled if in those circumstances the law attached liability for the death only to the gunman who actually fired the fatal shot."
Lord Phillips and Lord Judge added: "Mr Gnango and B had chosen to indulge in a gunfight in a public place, each intending to kill or cause serious injury to the other, in circumstances where there was a foreseeable risk that this result would be suffered by an innocent bystander.
"It was a matter of fortuity which of the two fired what proved to be the fatal shot."