Pc Ian Terry was married with two children
A firearms officer who fatally shot a colleague in the chest had been told to keep his gun pointed down during the training exercise, an inquest heard.
The officer who shot Pc Ian Terry, 32, earlier said he acted "instinctively", as Greater Manchester Police's firearms unit practised in a disused factory.
The ammunition used to kill Pc Terry, in 2008, was only to be shot at a person if "there was a threat to life".
Pc Terry was not wearing body armour, Coroner Nigel Meadows told the inquest.
The father-of-two, from Burnley in Lancashire, was shot at close range while holding an empty gun, as he played the role of an armed robber fleeing in a car.
The specialist firearms officer who shot him cannot be named for legal reasons, but is to be referred to as Chris throughout the five-week inquest.
Chris shot his fellow colleague with a single shot of Round Irritant Personnel (RIP) ammunition, the hearing was told. He was using a pump action shotgun at the time and was a foot away from Pc Terry when he fired the fatal shot.
Throughout the training exercise, the inquest heard, the 20 officers taking part were told to keep their guns pointed down and aim only for the car's tyres.
The aim of the specialist firearms officers was to burst the tyres of Pc Terry's "getaway" car and then pull the "suspects" out of the vehicle.
Mr Meadows outlined what happened shortly before the shooting.
He said: "Pc Terry extended his left hand through the window of the vehicle. Chris approached from the rear and held up his firearm to cover the vehicle and the occupants.
"At some point Chris removed the safety catch as he approached the vehicle.
"He approached with the shotgun and he fired it at Pc Terry from about a foot from his body.
"The shot struck him on the left side of his chest."
It was the first time Chris had played the role of an officer intent on demobilising the "getaway car".
Other officers were using weapons which fired paintballs.
The commander of the operation - under the pseudonym Francis - "had told the officers that there would be a shoot scenario which would involve a vehicle and the occupants and that they would have unloaded guns," Mr Meadows said.
"He also said the shotgun should only be used to deflate the tyre and to be pointed down at all times.
"Francis said he asked the group whether they understood the instructions and they replied they did."
However, Mr Meadows said that Chris, who had been interviewed shortly after the shooting, said he was not aware he was in a shoot scenario.
He was interviewed at the site of the training exercise in a disused warehouse in Newton Heath, Manchester.
Mr Meadows told the hearing: "Chris said he acted instinctively to the threat of the gun from Pc Terry, although it was appreciated it was a training exercise.
"He later told the Independent Police Complaints Commission that he acted by instinct and had not intended to shoot a colleague."
Despite first aid at the scene, Pc Terry died later in hospital.
A similar exercise was held a week before but no shots were fired because one of the officers involved did not want to be shot by paintball.
Giving evidence, Ch Insp Alan Wood, said: "Officers were trained never to point a firearm at anyone and never to put the finger on the trigger, unless it was justified in both cases."
Before the inquest at Manchester Civil Justice Centre, Mr Meadows said that at least 26 officers would be granted anonymity.
The hearing continues.