An 18-year-old from Streatham has been given a life sentence today after being found guilty of murdering nursing assistant Magda Pniewska in a "Wild West" shoot-out.

Miss Pniewska, 26, was caught in the cross-fire while two teenagers in hoodies fired at each other across a car park in New Cross.

She was talking on her mobile phone to her sister Elzbieta Luby in Poland when a bullet struck her in her forehead.

Both the teenagers ran off as Miss Pniewska collapsed on the bottom step of some stairs where the other teen, a 17-year-old, was firing at Armel Gnango.

Gnango, from Streatham Hill, denied murder but was found guilty by an Old Bailey jury last month. He was also found guilty of the attempted murder of a youth and had pleaded guilty to having a prohibited weapon.

Today, at Albans Crown Court, Mr Justice Cooke told him he must serve at least 20 years behind bars for the crimes.

The judge said: "The fact of the matter is that you went armed to find your man who then shot at you and a gun fight ensued.

"Either of you might have been killed. You plainly intended to kill the other and instead of either of you dying an innocent nursing assistant was killed instead."

During the trial the court was told it was not his gun which fired the fatal bullet in John Williams Close, in October, last year.

But prosecutor Brian Altman, QC, said Gnango was still responsible for the killing because he was involved in the gunfight.

The court was told a second youth, who had a red bandana over the lower part of his face, had also been arrested but not charged.

He had been named by Gnango but had denied being involved. Police had insufficient evidence to charge him, the court was told.