Pensioner had more than two million child abuse images - the largest haul ever seized by police in Scotland
Falkirk Sheriff Court heard that the size of the hoard recovered from MacPherson's home in Stenhousemuir, Stirlingshire, had “overwhelmed” officers' capacity to check and categorise it.
A pensioner amassed what's thought to be the largest haul of child sexual abuse images ever seized by police in Scotland, a court heard.
Alan MacPherson, 83, had over two million images.
Over 805,000 were formally identified by police as depicting child sexual abuse and given official classifications. Many of them were the most serious kind.
Falkirk Sheriff Court heard that the size of the hoard recovered from MacPherson's home in Stenhousemuir, Stirlingshire, had “overwhelmed” officers' capacity to check and categorise it.
Nearly 1.4 million images remained ungraded on just one of his devices alone.
Altogether, police seized nine devices – computers, phones, digital cameras, a USB stick and external drives – and child abuse images were found on all of them. Five of the devices were subjected to a full examination.
MacPherson was caught after police identified his IP address as being used to distribute the images online.
Prosecutor Rachel Wallace said that in July 2025 multiple images of child sexual exploitation, classed as Category A, the most serious kind, were uploaded via an anti-surveillance messaging app during an online chat with an undercover police officer.
The IP address that the images came from was discovered and traced to MacPherson's home and police mounted an early morning raid.
Ms Wallace said: “Due to the overwhelming quantity of child sexual abuse material recovered, a limited grading strategy was carried out.”
On one solid state storage drive alone, officers graded 698,924 child sexual abuse files – but had to leave a further 1.374 million files ungraded. The child victims were females, mostly aged nine to 15, but at least one possibly as young as seven.
Ms Wallace said: “Across all the devices examined, 805,306 indecent images were recovered, including both images and videos, including categories A, B and C.
“Police have advised us this is quite possibly the largest collection of child sexual abuse material ever seen by Police Scotland.”
MacPherson was arrested and interviewed and told police he had searched online for years for indecent images of children “for his own personal gratification”.
MacPherson, a first offender, of Crathes Avenue, Stenhousemuir, pleaded guilty at Falkirk Sheriff Court on Wednesday to downloading, possessing and distributing indecent images of children over more than 14 years, between January 1, 2012 and January 20, 2026.
Solicitor advocate Stephen Biggam, defending, said MacPherson is deaf and suffering from the eye condition macular degeneration.
Sheriff Craig Harris revoked MacPherson's bail.
He placed MacPherson on the Sex Offenders' Register, and called for background reports before a further hearing on September 8, at which time the length of his sentence and the time he will remain on the register will be dealt with.
He told him: “The offences are far too serious for me to proceed without a report.“
Given the nature and the scale and the time over which the offences have been committed, the risk you pose when you are at liberty, and the likely outcome by way of sentence, you must now be remanded into custody.”
He said he would ask for the report to cover the question of post-release supervision.
MacPherson showed no emotion as he was taken downstairs to the cells, but later wore a hood and partially hid behind a security guard as he was led out in handcuffs to a prison van.