Witnesses plea in murder probe

There is no known motive for Mr Wilson's murder

Police investigating the murder of a banker have been making a fresh appeal for help in tracing his killer.

Exactly a week after Alistair Wilson was shot dead, police officers have been questioning residents in Nairn in the hope of jogging their memories.

The 30-year-old Bank of Scotland executive was murdered on the doorstep of his home on Sunday, 28 November.

About 30 officers have been involved in the appeal, which includes door-to-door enquiries and questioning motorists.

Since his death, detectives have been trying to establish a motive to explain why Mr Wilson was killed.

It emerged on Friday that officers from Northern Constabulary were examining the possibility that the gunman could have escaped by boat.

They may have seen something which is of great significance but at the time didn't appear so to them Peter MacPhee Detective Chief Inspector

But no strong lead has emerged from the investigations so far.

Officers were hoping that Sunday's appeal would give them some information which moves them closer to finding Mr Wilson's killer.

Detective Chief Inspector Peter MacPhee said: "What we're trying to do is identify people who were on the move within Nairn either in their cars or on foot at the same time this weekend as were out last weekend.

"It's important that we identify as many people as possible.

"They may have seen something which is of great significance but at the time didn't appear so to them."

Mr Wilson was shot at his front door

Mr Wilson was getting his two sons, aged four and two, ready for bed at about 1915 GMT last Sunday when his wife Veronica told him there was a man at the door.

He took a mystery envelope from the suspect and left the doorway to speak to his wife.

Police have not given details of the conversation between the couple but when he returned to the door he was shot at point-blank range with what is thought to have been a small automatic handgun.

The gunman has been described as aged 35-40, stocky, clean shaven and was wearing a baseball hat and blouson jacket.

The BBC's Crimewatch programme has offered its assistance to detectives investigating the murder.