Colin Horner was fatally wounded in Bangor, Do Down
The PSNI say a man shot dead in a supermarket car park in Co Down had his three-year-old son in the car.
James Colin Horner (35), known as Colin, was shot and fatally wounded on Sunday afternoon in the car park of a Sainsbury's supermarket in Bangor.
Detective Superintendent Richard Campbell said: "It was hugely barbaric act and something that will undoubtedly live with this young boy for the rest of his life.
"My specific appeal lines relate to the vehicle he was driving when he left his partner’s home in the Balloo Road area of Bangor around 1.30pm.
"He was driving a black Nissan Pulsar car, registration XFZ 4706 and arrived in the car park around 2.30pm.
"I am keen to trace his movements during that one hour period."
Police are also looking to establish the movements of a red Ford Mondeo car, which was seen speeding away from the scene around 2.50pm just after Mr Horner was shot.
It is believed one of its occupants was wearing a dark hoodie type top, with possibly a dust mask covering his face.
This vehicle, which had fake number plates, was later found burnt out.
The PSNI say there may have been another vehicle which took the gunman and his accomplice away after they disposed of the car.
Detective Supt Richard Campbell added: "I would urge anyone who may have seen any of these vehicles to contact us.
"I would urge anyone who may have mobile phone footage, dash-cam footage or local businesses in the area with CCTV footage to come forward to detectives in Bangor.
"This was a totally reckless attack in the middle of a busy shopping area... We know at least three shots were fired with a stray bullet actually hitting another vehicle in the car park."