Cold lawsuit detectives re-investigating the shooting of a banker 20 years agone accidental they are keeping an unfastened caput to the murderer's motive.
Dad-of-two Alistair Wilson was changeable connected the doorstep of his household location successful the Highland seaside municipality of Nairn connected 28 November 2004. He aboriginal died successful hospital.
The execution remains unsolved and Mr Wilson's household have criticised constabulary efforts to find the killer.
Officers antecedently said they had a imaginable motive and suspect, but the elder detective overseeing the caller probe said determination were galore unfastened lines of probe and thing was being discounted.
Mr Wilson, 30, and his woman Veronica had been bathing their 2 young sons and getting acceptable to work them a bedtime communicative erstwhile the slayer came to the door.
A bluish envelope, which had the sanction Paul connected it, was handed to Mr Wilson connected the doorstep.
He went wrong and showed it to his wife, but the envelope had thing inside.
When Mr Wilson returned to the doorway helium was shot.
Last year, constabulary said they had a imaginable suspect aft antecedently suggesting a readying quality implicit decking astatine edifice adjacent the Wilsons' location was a apt motive.
But connected the 20th day of the murder, Det Ch Supt Suzanne Chow vowed the re-investigation would beryllium "full and thorough".
She told BBC Scotland News: "We are not discounting immoderate avenue astatine this clip and determination a fig of lines of probe unfastened to us.
"We are taking it close backmost to what happened successful 2004.
"We are being wholly impartial, wholly unfastened minded and ensuring a thorough probe is carried out."
The elder detective said she had met Mr Wilson's household to "build spot and confidence" with them.
And she said a squad of officers were collating and evaluating 20 years of evidence.
The acold lawsuit probe volition besides instrumentality vantage of caller techniques and technologies that were not disposable successful 2004.
Officers who person dealt with akin types of cases with constabulary forces successful England, Wales and internationally are besides being consulted.
Police Scotland has acceptable up a large probe nationalist portal wherever radical tin taxable files and accusation anonymously.
Det Ch Supt Chow, who has been progressive successful different acold cases including the 1984 execution of Mary McLaughlin, said the re-investigation would instrumentality arsenic agelong arsenic was needed.
She added: "It is simply a truly analyzable probe and I americium committed and determined to uncovering answers for Alistair's family."
The re-investigation, called Operation Sabine, was ordered by Scotland's apical instrumentality serviceman successful September.
Since the murder, constabulary person released assorted pieces of accusation connected the killer:
- He was aged betwixt 20 to 40 years old
- He was astir 5ft 7in and wearing a shot headdress and jacket
- The weapon was a Haenal Suhl Model 1 Schmeisser's patent handgun, manufactured betwixt 1920 and 1945 astatine the Schmeisser mill successful Germany.
- The ammunition was .25 calibre made by Sellier and Bellot successful the Czech Republic betwixt 1983 and 1993.
In December past year, Mr Wilson's household complained to the Police Investigation and Review Commissioner (Pirc) astir the handling of the force's investigation.
Police Scotland and the Crown Office said astatine the clip they had met the household to sermon the matters raised by them.
Then successful September this year, the household said they had "lost confidence" successful the nationalist unit and labelled it "incompetent".
Mrs Wilson and her lad Andrew, who is present 24, told the Press and Journal paper that their narration with constabulary had "steadily deteriorated" successful the past 18 months.
The household said this was owed to unresolved issues not being decently addressed.