A former US Marine was found guilty today of the cold-blooded murder of Bradford policeman Ian Broadhurst on Boxing Day last year.

David Bieber, a bouncer and steroid abuser who is wanted in the US for a murder plot, was also convicted of the attempted murders of two of PC Broadhurst's colleagues.

A jury of six men and six women at Newcastle Crown Court convicted Bieber, 38, a day after retiring to consider verdicts.

They were unaware that he was a drug dealer who had fled to the UK from Florida where he was wanted by police over a plot to hire a hitman to kill a love rival. He was also suspected of hiring the same gunman to murder his former girlfriend, but the attempt on her life failed.

PC Broadhurst, 34, of Birkenshaw, was gunned down during a routine check on a stolen vehicle in Leeds.

His colleagues PCs Neil Roper, 45, and James Banks, 27, were shot but survived.

Bieber, who was driving the stolen BMW, fled the scene, triggering a manhunt which ended when he was found holed up in a £34-a-night hotel in Gateshead. He had hidden the murder weapon under a mattress.

Bieber, who was using the name Nathan Coleman at the time, tried to convince the jury the killer was a friend - dubbed "Mr X" by the prosecution - whom he refused to name, claiming he was a loyal friend he would not "stab in the back".

The jury, which retired yesterday afternoon, delivered unanimous verdicts on all the charges.

Throughout the trial, identity remained the central issue for the jury to consider.

Bieber tried to convince the jury that a mystery man carried out the horrific execution-style shooting.

The issue of identity was so crucial that the trial judge, Mr Justice Moses, imposed strict reporting restrictions.

Reporters were prevented from describing Bieber, including the colour of his hair, which was dyed ginger at one point while on the run, for fear of prejudicing witnesses.

Addressing the jury, Bieber's barrister Michael Beckman QC said the issue of identity was at the core of the case.

He told them: "Fundamental to this case is the question of identification."

Bieber went to great lengths to try to mask his identity and his previous life in America.

The bodybuilder came into the UK through the Kent port of Ramsgate from France in September 1996. He arrived with a false passport under the new name of Nathan Wayne Coleman and gave a date of birth of June 28, 1968.

He was given six months leave to remain in the country as a tourist, which was then extended every six months until he married his girlfriend Denise in 1997.

Even she was fooled by his double life and knew nothing of his previous past in Florida or his previous name. The couple divorced in 2002.

Police were later to discover that Bieber had armed himself with two more false identities.

He was found with a birth certificate and social security card in the name of David Michael Dudgeon, an American citizen born in 1968, when he was arrested.

Another birth certificate was also seized by detectives with a third name on it.

In addition to these false identities, Robert Smith QC, in the absence of the jury, disclosed that a piece of paper listing the names and dates of birth of seven people was also discovered in the bodybuilder's possession.

The names belonged to children who had died at the same time as Bieber was born, the judge was told.

But it was the name Nathan Wayne Coleman that the American would use throughout his stay in the UK, opening bank accounts with it and taking out tenancy agreements and membership of gyms.

The jury heard that Bieber worked as a doorman in Leeds, kept fit at a local gym and was known to colleagues by his assumed name.

There were betting accounts with bookmakers as Coleman, and the flat he rented was in the assumed name, the court heard.

Shortly after carrying out the shooting, he told a bed and breakfast proprietor in Bradford that he was called Rick, was a travelling vitamins salesman and needed a place to stay following a row with his girlfriend.

When the owner asked about his North American accent, Bieber told him he had gone out with a Canadian girl and it had "rubbed off".

While on the run Bieber once again tried to cover his tracks and booked into a Gateshead hotel in a ridiculous disguise.

His "Deirdre Barlow-style" disguise proved his downfall. Hotel staff tipped off the police and he was arrested by armed officers.

Hotel worker Victoria Brown said Bieber arrived at the hotel wearing very large glasses and a woolly hat - likened to the size of spectacles made famous by the Coronation Street character Deirdre Barlow and the hat that odd job man Benny wore in the defunct soap Crossroads.

Bieber did his best to play havoc with the criminal justice system from the time of his arrest on New Year's Eve.

During his first court appearance, he insisted he should be referred to as Nathan Coleman and not David Bieber as he desperately tried to hide behind his assumed identity.

He changed his defence team on a number of occasions, putting PC Broadhurst's family through extra misery as court appearances had to be rearranged and postponed.

His trial even had to be postponed for a month at the last minute when the American decided once again to sack his legal advisers. A new High Court judge had to be found to try the case.

Every time Bieber appeared in court, police provided a show of the highest security measures.

These included having armed police inside and outside the court buildings, thorough security checks for all those attending and even a helicopter accompanying his movements.

During the trial, Bieber's only glimmer of hope lay in PC Neil Roper's failure to pick him out in a video identity parade.

Bieber's image was among 12 presented to PC Roper - who came face to face with the gunman for ten minutes in the back of the police car - but he failed to pick him out as he lay in hospital recovering from his injuries.

Bieber could also rely on the fact that no one got a good description of the gunman as he fled the scene.

His desperation continued in court where he claimed a mystery friend from Florida, referred to as Mr X, carried out the shooting.