Detectives were last night still trying to piece together events leading up to the murder of David Beesley, 28, who was found in his office at the West Didsbury store after being shot in the head.
Officers believe the motive was robbery but by last night had not determined whether anything had been taken from the safe in Mr Beesley's office.
Links between yesterday's murder and an armed raid on Monday at another Kwik Save store two miles away in which £12,000 was taken were also being investigated.
Mr Beesley, a single man from the Offerton area of Manchester, was in his office at 7am when the killers walked in and shot him in the head and once in the stomach.
Det Supt Bernard Rees, leading the murder hunt, said two men had been seen outside the store as Mr Beesley arrived for work alone. Cleaners arrived 15 minutes later to find the front door unlocked, which was unusual, but carried on working at the back ofthe store thinking Mr Beesley was working in the office. His body was found at about 7.45am.
Det Supt Rees said: "The manager would have been the first person to arrive. Another member of staff arrived and went to look for the manager. He found him crouched on floor in his office. He appeared to have been shot in the head. He was already dead.
"The probable motive is robbery but we cannot yet confirm whether anything was taken. There was no sign of a break-in. We don't believe the robbers were waiting for the manager inside the store."
But no weapon was found at the scene and detectives were still waiting for the results of the post-mortem examination to determine how Mr Beesley died.
Alan Faulkes, the supermarket chain's divisional director, paid tribute to Mr Beesley. "He was a very bright young star who was tipped for top. The rest of the staff are all being comforted. They are all devastated.
"It's an appalling incident but unfortunately whenever you deal with cash then there is a risk. It's an appalling waste of a young life."
Samantha Moran, 20, a Kwik Save worker, said yesterday: "He was the best boss I ever had. He would do anything to help you out. I can't believe what has happened."Reuse content