Never-before-seen images unearthed after the Moors Murderer's death show his would-be victims playing at Myra Hindley's former school.
They were taken by camera fanatic Brady as he and his lover scoured the streets near their home and imagined carrying out the murders they went on to commit.
The twisted pair planned the abductions and killings of their child victims in meticulous detail before Brady documented them with photos.
He then developed the images using darkroom equipment he had in the upstairs bathroom of his home on Westmoreland Street in Longsight, Greater Manchester.
The sinister collection, which featured pornographic photos of Brady and Hindley, was seized by police after the couple's arrest in 1965.
Photos including shots of the pair's victims and the graves they buried them in on Saddleworth Moor were later used as evidence by prosecutors.
Exclusive access has now been obtained to some of those photos, which are being revealed to the public for the first time.
The haul includes images taken by Brady through the window of his van which show children at Ryder Brow Secondary Modern - the school Hindley attended.
The pictures were taken as Brady and Hindley spied on pupils taking part in what appears to be a PE lesson.
Another photo, taken through the black metal bars of the school fence, shows older boys wearing sports kits playing a football match.
The collection also contains black-and-white shots of Brady standing in his house wearing suit trousers, a dark cardigan and tie.
The notorious paedophile and murderer - who, with Hindley, killed five children aged between 10 and 17 - poses with his hands in his pockets and smiles for the camera.
Others believed to be taken by Brady as he practised his photo-taking skills show a dog, a cat and Brady's mother Peggy Stewart at the home they shared.