Marvyn Bradshaw died outside a pub in Nottingham

Jamie Gunn, 19, a doorman from Nottingham, died nine days ago from pneumonia after suffering from depression following the shooting.

He was in a car with Marvyn Bradshaw, 22, outside a pub in August 2003 when his friend was shot.

Michael O'Brien was jailed last month after he was found guilty of murdering Mr Bradshaw.

'Broken heart'

The murder of O'Brien's mother and stepfather at a bungalow in Lincolnshire on Sunday is being linked to the Nottingham killing of Mr Bradshaw.

Joan and John Stirland, 53 and 55, left Nottingham after O'Brien was convicted of murder.

It is believed they were in hiding in the Lincolnshire coastal village when they were tracked down by gunmen and murdered on Sunday.

Jamie held Marvyn in his arms after he had been shot. Julie, mother of Jamie Gunn

Mr Gunn's mother, Julie, 36, blamed her son's death from pneumonia on the murder he witnessed as Mr Bradshaw was shot dead outside the Sporting Chance pub in Top Valley.

She told the Nottingham Evening Post he was glad that justice had been done and O'Brien was behind bars, but he seemed on a mission to "self-destruct".

She said: "Jamie held Marvyn in his arms after he had been shot. I think he may as well have died then, too. He went downhill after that. He could not cope."

Mr Gunn's health declined and he was found dead by his brother and sister at the family home in Bestwood, Nottingham, on 2 August.