Alistair Wilson, pictured on a family outing on the day he was murdered

Veronica Wilson, 33, has been living in a secret location under armed guard since her husband was gunned down on the doorstep of their home.

She said the family still have no idea why he was shot dead at the house on the town's Crescent Road on the evening of Sunday, 28 November.

Forensic tests are still being carried out on a gun found nearby on Wednesday.

Mrs Wilson was speaking in public for the first time since she answered the door to her husband's killer 12 days ago.

'Absolute disbelief'

She is the only person to have seen the murderer that night.

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

Officers have said they are not yet in a position to issue a photofit image of Mr Wilson's attacker.

Mrs Wilson has been staying at a secret location with the couple's two young sons for fear she might become a target.

She clutched a tissue as she spoke of her horror and grief at what had happened.

I cannot even call the person responsible a human being, because I can't understand how a human being would do this Veronica Wilson

"I am just still in absolute disbelief," she said.

"There was no known reason for this to happen, so I cannot even begin to understand why someone has done this, not just to my husband but to all of us - I don't even know if it is true or real.

"It would make it easier if I thought there was something in my husband's life but it just makes no sense.

"For me and the boys to move on I need to know who did this and why - I can't imagine ever moving on without knowing who and why."

Dressed in black and softly spoken, Mrs Wilson said she could not imagine this Christmas without her "third big kid".

Workmen found a gun in a nearby drain on Wednesday

Mrs Wilson broke down at times as she spoke about the person responsible for her husband's death.

"I can't believe that this person has cold bloodedly killed my husband, my children's father," she said.

"I can't believe that they did this and that they did it on our down doorstep with all of us in the house.

"There was no reason for this to happen, but even if they had something against Al, they have taken away our home.

"For me to lose my husband in any normal circumstances would be hard, but how can you explain to my boys that their daddy has gone?"

Information plea

She said the hardest part would be if she did not find out who did this.

"I cannot even call the person responsible a human being, because I can't understand how a human being would do this," she added.

"At the moment everyone is doing everything they can to help us, and that is a great comfort, but someone out there does know something and even if it is to rule out any suspicion, they must come forward and tell the police."

The couple met in Mrs Wilson's home town of Fort William and got engaged after just six weeks and married in 1998.