At the scene of crime anything might be relevant.
Sue Black was a teenage schoolgirl in Inverness when Renee MacRae and her son Andrew vanished in November, 1976.
Yesterday, the renowned forensic anthropologist was back near her home city hoping to help solve one of Scotland’s most enduring mysteries and a crime etched in her memory.
Professor Black, of the Centre for International Forensic Assistance, has searched sites in Iraq and Kosovo for evidence of war crimes but has now turned her attention to a disused quarry, 12 miles from the Highland capital.
For the next few weeks a team of experts will comb the site just off the main A9 trunk road where it is thought the bodies of Mrs MacRae and her son may have been dumped.
Some 2,000 trees have been felled to clear the site for a fresh investigation at Dalmagarry, near the spot where Mrs MacRae?s burnt-out BMW was found nearly 28 years ago.
A mechanical digger was brought in yesterday to start excavating 20,000 tons of soil and rock ahead of a painstaking search for clues and, it is hoped, the discovery of remains of the missing pair.
The police file on the case was reactivated after former officer, Det Sgt John Cathcart, said he was convinced the bodies were in the quarry. He said that a few months after Mrs MacRae and Andrew disappeared he detected the smell of rotting flesh in the quarry, but a full search was never completed.
However, last month Ian Latimer, Chief Constable of Northern Constabulary, announced that after a cold-case review of the deaths, he now had a “specific reason” to carry out a further search.
Prof Black, who works at Dundee University’s anatomy and anthropology department, said her task will be to identify any remains found, but with the passage of time and a three-year-old possibly involved, the team could be looking for pieces of evidence “no bigger than the end of your thumb”.