Police are urging people to watch a TV reconstruction to help them crack the unsolved murder of Lee Erdmann.
Lee was gunned down in the Wellington pub on Regent Road, Ordsall on Saturday September 10, 2011.
Lee's mother is making a direct appeal on BBC's Crimewatch programme.
The 37-year-old had been standing at the bar in the lounge of the pub, at around 2.50am, when another customer he had been talking to calmly shot him twice.
There had been no argument between the two men or anyone else. CCTV was captured of Lee from the Hyde Park pub, Salford, several hours before the incident.
Police have also issued footage of the crime scene, showing where Lee had been standing when he was shot. But the hard drive which would have contained CCTV footage of the murder had been stolen.
Hundreds of people have been interviewed as part of the investigation. But despite numerous appeals, those responsible for the crime are still at large.
A reward of £50,000 is being offered for information leading to the arrest and conviction of those responsible.