A fresh appeal for information has been made on the third anniversary of the murder of Jim Donegan.
The 43-year-old was shot dead outside a school in West Belfast as he waited to collect his teenage son on December 4, 2018.
He was sitting in his red Porsche Panamera in Glen Road when he was attacked.
A murder inquiry to find the lone gunman police believe carried out the killing remains ongoing.
PSNI Detective Chief Inspector Ray Phelan described the murder as a "ruthless execution carried out in broad daylight by a lone gunman in front of hundreds of innocent schoolchildren and their parents".
He said: "He didn't care who saw him or whom he traumatised. He showed total contempt for anyone who was in the vicinity.
"I believe that the information police require lies within the community and today I am making an appeal to the community: if you have any information, no matter how insignificant it may seem, please come forward to police. Help us to bring this cold-blooded murderer to justice."
Mr Phelan added: "Jim was a husband, a brother, a father to two sons, and a stepfather. Ask yourself how you would feel if this was your loved one who was taken away in such a cold and callous fashion. Jim's family deserve answers and justice.
"If you have information, call police on 101 or submit a report online at www.psni.police.uk/makeareport."
A PSNIO spokesperson said: "Alternatively, information can be provided to Crimestoppers anonymously on 0800 555 111 or online at www.crimestoppers-uk.org ."