A police officer was shot in the head at point blank range as he pleaded for his life, a court has heard.
Pc Ian Broadhurst was shot and killed on Boxing Day
David Bieber "calmly" shot 34-year-old Pc Ian Broadhurst in Leeds last Boxing Day after firing at Pcs Neil Roper, 45, and James Banks, 26, a jury was told.
The 38-year-old denies murder, two counts of attempted murder, possessing a firearm with intent to endanger life and possessing 200 9mm bullets.
Mr Bieber, of Oakwood, Leeds, admitted possessing ammunition without a permit.
Jurors heard how the last few seconds of Pc Broadhurst's life were recorded by the officers' patrol car equipment.
Pc Broadhurst, who had already been shot in the chest, was heard to scream, "Do not shoot me. Please no" as he lay seriously injured on the ground.
Opening the prosecution's case at Newcastle Crown Court, Robert Smith QC said Mr Bieber had fired four shots from a 9mm semi-automatic handgun in just eight seconds.
The first shot hit Pc Broadhurst in the chest. The second shot was fired at Pc Roper as he ran away and a third hit Pc Roper in the shoulder, Mr Smith said.
"A period of five seconds had lapsed following the firing of the fourth shot, during which the accused took the handgun in both hands in a position standing over Pc Broadhurst, aimed and shot him in the head."
Mr Smith said Pc Roper and Pc Banks were hit as they fled in opposite directions away from the gunman.
The court heard Pc Banks escaped injury or death by a "miracle" when a bullet ricocheted off his radio.
"It was only after this that the man stood over Pc Broadhurst and delivered
the fifth and fatal shot to that officer's head," Mr Smith added.
Mr Smith said the gunman had used a handgun "with accuracy" to shoot all three officers rather than face arrest.
"But his motives went further than simply avoiding arrest," he added, "for having shot Pc Ian Broadhurst he deliberately and purposefully went at close range to that officer, and calmly shot him in the head before making good his escape."
The court heard that Mr Bieber had taken the alias Nathan Wayne Coleman from a dead child in the US and held a US passport, a UK driving licence and British bank accounts in the assumed name.
The Home Office reported that Nathan Wayne Coleman arrived in the country on
26 September 1996 and, having married a British citizen, he was given permission to stay.
Mr Smith said: "It is clear, say the prosecution, that Nathan Wayne Coleman and David Francis Bieber are one and the same man."
After the shooting, the defendant stayed that night at the Park Grove Hotel in Bradford where he claimed to be a travelling salesman.
Mr Bieber was arrested by armed officers from Northumbria Police at a hotel in Dunston, Gateshead, during the early hours of 31 December.
Officers recovered a weapon, a large amount of ammunition and a grey Nokia mobile phone from the hotel room where Mr Bieber was staying, the court heard.
Forensic tests showed that the weapon, a 9mm self-loading pistol was the same one used to shoot dead PC Broadhurst and shoot at Pcs Roper and Banks.
A one in one billion DNA match linked Mr Bieber to a chocolate bar wrapper found in the back of the police patrol car, Mr Smith said.
His fingerprints also matched items found in Coleman's flat, and included different parts of a gun cleaning kit found in the flat, he added.