A "professional or contract killing" was carried out by four County Down men, a court has heard.
The men are awaiting sentence after pleading guilty to the murder of father-of-two Colin Horner in a supermarket car park in Bangor.
The 35-year-old was shot dead by a lone gunman dressed in black, outside Sainsbury's on Balloo Link in May 2017.
His three-year-old son Oscar witnessed the shooting.
Police linked the killing to an ongoing South East Antrim UDA feud in which Geordie Gilmore was also killed in March 2017 in Carrickfergus.
Newtownards men Alan James Wilson, 30, of North Green, Joseph Blair, 35, of Shackleton Walk, Robert Ralph, 47, of Donaghadee Road, and 31-year-old Bangor man Ryan Graham Smyth, of Windsor Gardens, all pleaded guilty.
The men have been given automatic life sentences but will find out next week the minimum time they must serve before being considered for parole.
During Tuesday's tariff hearing, the court heard that on the day of the murder, a gunman dressed in black had left a burgundy maroon Ford Mondeo parked some distance away from Mr Horner's Nissan Pulsar, parked outside the supermarket.
The gunman vaulted a low hedge and approached Mr Horner, shooting him several times, and firing several times more after he fell to the ground.
It was a mere 20 seconds from the time the gunman got out of his car, carried out the shooting, returned to his car and left again.
Mr Horner and his partner did not normally shop at Sainsbury's and the court was told that he may have been trying to stay in public places where he felt safer, having realised that he was being followed.
The prosecution outlined what police believed was an earlier murder attempt some 11 days earlier when masked men were observed in a vehicle parked near Mr Horner's home.
It left the area when a neighbour became suspicious. The same vehicle was used in the eventual murder.
The court also heard that detectives established more than 200 sightings of vehicles connected with the shooting in the hours before Mr Horner was murdered.
There was also evidence of many phone calls and texts between the four men who were convicted.
A prosecution barrister told the court it may be considered to be a paramilitary murder, since it was a "planned operation" and "in the nature of a professional or contract killing".
He said that, although unable to identify the actual gunman, it was the prosecution case that the four men were "part of a joint enterprise involving the targeting and deliberate killing of Colin Horner".
However a defence barrister for Joseph Blair disagreed that it was a professional killing, telling the judge that "the amateurish nature of this episode is plain for all to see".
In mitigation, a barrister for Ryan Smith told the court that there was "clear control and direction in this case", meaning that another individual had directed the four guilty men in their actions.
During the hearing the four men waved and give the thumbs-up to family and friends as they had last week after pleading guilty to murder.
The judge told the men he has already sentenced them to life, but he wished to review the prosecution evidence and the submissions made by their defence counsel before determining their minimum sentence.
Adrian Gordon Price, 48, of Bristol Park, Newtownards, and 24-year-old Conlig woman, Terrie Aicken, from Green Road have pleaded guilty to the lesser charge of withholding information in June 2017, and will be sentenced next week.
The court heard that all the guilty pleas avoided a trial which could have lasted five to six weeks.