Shown in silence only to Lord Cullen and the legal teams, glimpses on their television monitors could be seen of bare-chested small boys, dressed only in swimming trunks, running around doing exercises in a gymnasium.
The inquiry has heard about Hamilton's obsession with images of the boys who attended his clubs. Police who searched his flat after 13 March when he shot dead 16 primary one children and their teacher, discovered piles of photographs of young boys.
Witnesses have also told of Hamilton showing them video tapes of boys, mostly taken at camps he organised. A neighbour also told the inquiry of a large fire in Hamilton's garden where he had appeared to be burning plastic boxes that could have been tapes.
Yesterday most of the 25 television monitors dotted around the inquiry hall in Stirling were blank as the lawyers sat in silence watching theirs - some of which were visible from the public area of the venue.
As the tape was played, showing boys doing roll-overs and sit-ups, it was clear that the camera operator had focused for a long time on one small child as he was doing around 20 sit-ups. The exercise was evidently causing the boys a great deal of effort.
Ian Bonomy QC, for the Crown, said the compilation also showed boys standing in a pose with their chests out and looking "very tense".
The mother of one seven-year-old also told the inquiry how she had become concerned after her son went to one of Hamilton's clubs. After collecting her son from a session, Hamilton walked with them on their way home. But the woman felt some unease in Hamilton's presence and because she felt "uncomfortable" walked past her house. She said Hamilton later gave her a video which "disturbed" her as it appeared to focus on boys between their waist and knees.
When she and Hamilton had parted company that night, Hamilton had asked about her son - and seemed to be "more interested than he should be" in him. She contacted a friend who knew a policeman and was later told there was nothing illegal in the video.
After evidence given to the inquiry on Wednesday which revealed that police in Central Scotland had considered revoking Hamilton's gun licence in 1991 but had opted to take no action, retired detective superintendent John Millar yesterday told the court that although Hamilton was under investigation for his conduct of a boys' summer camp, firearms did not feature at that time.
While Hamilton was viewed as an "oddball" with a liking for young boys, no proceedings had ever been launched against him. Any move to revoke Hamilton's licence would probably have been overturned by a court, Mr Millar said.
In a statement which will have confirmed public fears that the acquisition of firearms is now relatively easy in Britain, Mr Millar said : "If his [Hamilton's] certificate had been refused, and his guns were taken away, and he still felt the way he did [at the time of] this terrible tragedy, there is no doubt in my mind he could still have got possession of firearms."
The inquiry continues on Monday, for its third week.Reuse content