John Pordage, 34, was killed by a single shot to the chest at a BP garage in Chelmsford, Essex, following an argument with a group of teenagers.
He was returning from a nightclub and on his way to buy cigarettes when he was shot at around 2.10am on August 5 last year at the garage in Baddow Road. He later died in hospital.
Police believe the man who may have fired the gun- Bradley Blundall could be hiding in Ibiza. A £10,000 reward for information leading to his arrest is on offer.
Two teenagers have stood trial in connection with the shooting. A 16 year old, who can't be named, was found not guilty of murder but admitted perverting the course of justice and handling stolen goods. He was sentenced to eight months detention last week. 18-year-old Saul Stanley was jailed for five years for firearms and other offences.
The CCTV footage shows Mr Pordage arriving at the garage in his work van with a friend. A blue Ford Fiesta is at the garage, with the three boys, the 16-year-old, Stanley and the alleged shooter Bradley Blundell, in the back of the car.