Pensioner who amassed 'largest collection of child sex abuse material' seized by Police Scotland jailed

A pensioner who amassed what’s thought to be the largest collection of child sexual abuse material ever seized by police in Scotland has been jailed for four years.

Alan MacPherson was told by a sheriff that the scale of his crime was “exceptional”.

In addition to his jail term, MacPherson was made subject to a three year extension to his jail sentence, during which time he will be subject to licence conditions and can be recalled to jail if he reoffends.

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 sex abuse images were found on all of them. Five of the devices were subjected to a full examination.

MacPherson was unmasked after police identified his IP address as being used to distribute child porn online and his home in Stenhousemuir, Stirlingshire, was raided.

MacPherson, a first offender, appeared for sentence after pleading guilty last month to downloading, possessing and distributing child porn over more than 14 years, between January 1, 2012 and January 20, 2026.

After reading social background reports, Sheriff Mayram Labaki told him: “The scale of your offending is exceptional.

“The quantity [of images] was so great that a substantial proportion could not be examined and categorised by forensic examiners.

“Every image records the abuse or exploitation of a child. The possession and circulation of such material perpetuates that abuse.”

MacPherson is deaf and suffering from the eye condition macular degeneration.

Sheriff Labaki said she recognised that a jail sentence would “bear heavily” upon him because of his age and physical condition.

She said: “Those matters are significant but they cannot outweigh the gravity of this offending. Your age does not alter the gravity of the material, nor that your conduct was deliberate, sustained over 14 years, and involved an extraordinary quantity of images.

“Your views towards your offending and your victims are unconscionable…. I refer specifically to the passages in the report where you state that not only were the children consenting, but they were willing participants.

“Your attitude is unremorseful”.

Solicitor-advocate Stephen Biggam, defending, said MacPherson would “steadily lose his eyesight” due to macular degeneration.

He said: “The court might take the view that will eliminate or significantly mitigate any risk going forward.

“His wife has served divorce papers on him.

“It’s been made plain to him that his wife, his son, and 99% of people in general, want nothing more to do with him.

“There is a great deal in his life that will be lost to him – particularly in terms of his retired hobbies, being involved in the archive in relation to dancing.”

Prosecutor Rachel Wallace told the court earlier that in July 2025 multiple images of child sexual exploitation, classed as Category A, the most serious kind, were uploaded via the anti-surveillance messaging app Session during an online chat with an undercover police officer.

Despite Session’s emphasis on user confidentiality and anonymity, 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 was 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 showed no emotion as he was taken downstairs to the cells.

In addition to the jail sentence, MacPherson was placed on the sex offenders’ register for life.