Police are investigating new forensic evidence in the case of murdered teenager Stephen Lawrence who was stabbed to death in south London in 1993.The 18-year-old was killed in a race-hate attack by a gang of five white youths in Eltham 14 years ago but no one has ever been convicted over his death.Three men - Gary Dobson, 32, Neil Acourt, 32, and Luke Knight, 31 - were acquitted in 1996 after a private prosecution brought by the Lawrence family collapsed at the Old Bailey.Two other men, Jamie Acourt, 31, and David Norris, 31, were also arrested after Stephen's murder but never stood trial as the case against them collapsed before reaching court.The abolition of the double jeopardy rule two years ago, which prevented defendants being tried twice for the same crime, means the men could potentially face another trial.Scotland Yard said the inquiry into Stephen's death was subject to regular reviews, as was the case with all unsolved murders."An opportunity to see if the forensic work can be re-visited in the light of new technology is standard practice and is being adopted in the murder of Stephen Lawrence," said a spokesman."As the result of a forensic opportunity coming to light new DNA samples are being taken from individuals who may have come into contact with Stephen at the time, or prior to his death, such as his family, police officers, ambulance and medical staff."Stephen's father Neville Lawrence, who now lives in Jamaica, said he had never given up hope of bringing his son's killers to justice."I've been waiting for 14 years, so I won't get my hopes up yet, but it sounds fantastic news," he said."We have tried many times before, as you know, but if we manage to get justice for Stephen this time, it would make me really, really happy."It's the very least that my lovely son deserves."© Independent Television News Limited 2007. All rights reserved.