Police have released an image of a potential witness to the murder of Jim Donegan two years ago.
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.
A murder inquiry to find the lone gunman that police believed killed him remains ongoing.
While 15 arrests have been made in the police investigation, no one has yet been charged with Mr Donegan’s murder.
Detective Chief Inspector Peter Montgomery described the murder as a “a chilling and callous execution” carried out by a lone gunman in front of hundreds of innocent school children and their parents.
He said the man, whose image has been released, may be able to help with the probe and urged him to come forward.
“I am hoping the male, who we have released images of today, will contact us as we believe he may be a potential witness, and he may hold vital information about what happened,” he said.
“My appeal to this male is, please, come forward to us. You might have information which is key to piecing together the events which resulted in the death of Jim Donegan. What you saw on that day or what you know may make all the difference.
“I would also appeal to anyone who believes they know the male pictured in these images to contact us.”
Detective Chief Inspector Montgomery added: “I have said before I am confident the answer to finding those involved in Jim’s murder lies within the community.
“Today, I am appealing again to anyone who has information which could be significant to please, pick up the phone and tell us what you know.
“Jim was a husband, a brother, a father to two sons and a stepfather. His loved ones deserve to have answers and the community deserves to have this dangerous man who killed him sent to prison for this callous murder.
“If you have information, call us 101.”