Police have admitted there appears to be no motive for the murder of a bank manager on his doorstep in the Highland town of Nairn.
Alistair Wilson, pictured on a family outing on the day he was murdered
Alistair Wilson, 30, was shot in the head at his home in Crescent Road on Sunday evening after his wife opened their door to the killer.
The couple were putting their two young sons to bed when the man called.
Asked about a motive, Detective Superintendent Gordon Urquhart said there appeared to be "absolutely none".
Veronica Wilson answered the door at about 1915 GMT on Sunday to a man who asked to speak to her husband.
Mr Wilson had been putting their sons, aged four and two-and-a-half, to bed and when he approached the door, he was "brutally gunned down", police said.
His wife ran for help to the Havelock Hotel, which is opposite the couple's home. Mr Wilson was taken to hospital in Inverness where he died.
The killer turned left along Crescent Road and headed on foot towards Marine Road.
Police want to question a stocky, clean-shaven man aged 35-40, who was wearing a baseball cap and a blouson jacket.
Nairn, which has a population of about 11,000, is 16 miles east of Inverness on the Moray Firth coast and is a popular Scottish holiday destination.
Detective Chief Inspector Peter MacPhee, who is leading the investigation, said: "There would appear to be absolutely no motive for this despicable crime.
"Alistair was an upstanding member of the community in Nairn and well-known in business banking circles."
Originally from Ayrshire, Mr Wilson joined the Bank of Scotland as an accountancy and business law graduate.
He started in the Fort William branch before moving to the private finance initiative and specialist lending sections in Edinburgh.
The door where Alistair Wilson was shot dead
Mr Wilson moved to business banking in Inverness in November 1999. He and a colleague formed a team in May last year to improve access to banking products for businesses in the Highlands and Islands.
A bank spokesman said: "Alistair was a highly valued colleague and our thoughts are with his family, friends and colleagues at this difficult time."
DCI MacPhee went on: "I have formed a sizeable inquiry team to carry out an investigation and have assistance from the Grampian Police laboratory and from the ballistics section at Strathclyde Police.
House-to-house inquiries are being carried out and a family liaison officer has been appointed to look after Mrs Wilson and her sons.
"There is currently a high visibility police presence in the town which will continue for as long as necessary and I also have to state that a number of officers on patrol are armed," DCI MacPhee added.
"I would again appeal to members of the community to contact police if they have any information at all, in particular as this incident happened in the early evening and there may have been dog walkers out in the Crescent Road area."
Scenes of crime officers scour the scene for evidence
Detective Superintendent Gordon Urquhart said: "It is almost bizarre, these things don't happen in Nairn. We are completely surprised, it is a quiet place."
Part of the inquiry is investigating whether Mr Wilson's job as a bank manager was linked to his murder.
"We are looking at all areas that will lead us on and give us further information on the motive and who may have carried out this terrible attack," Det Supt Urquhart added.