IN a trial that laid bare the most horrific facets of his murderous past, Robert Black betrayed no emotion.

The balding 64-year-old, now an ageing shadow of his menacing mugshot of 20 years ago, occasionally raised his eyes to the ceiling and asked for his specialised hearing device to be replaced.

Born in 1947 near Falkirk in Scotland to single mother Jesse Hunter Black, “Smelly Robbie Tulip” was put up to be fostered within weeks.

The couple who took him in -- the Tulips -- were in their 50s and lived in Kinlochleven in the West Highlands. Within 11 years both had died and Black was placed in a Falkirk children’s home.

He claims his desire to self-abuse and his fascination with young girls had already developed well before then.

“I’d like to know where it came from,” he told police years later. “I’ve got the two unfortunate distinctions now -- I’m attracted to young girls and I abuse myself. Someone once said to me, a so-called doctor, that it had to be a learned behaviour.”

As a 12-year-old, he was accused of trying to rape a young girl. No charges came of it, but as a result Black was moved to an all-boys home in Musselburgh, where he claims he was sexually abused by male staff.

Peter Ritchie, a retired detective superintendent from Lothian and Borders Police who spent five years at Europol, was at Musselburgh Grammar School at the same time as Black. He spent four years working on the Caroline Hogg investigation.

“I remember he broke my cousin’s nose in a fight,” he says. “The kids from the Red House home were hellishly treated because they were different.

“I will never forget the day we were told that the body found in England was Caroline Hogg’s. It was incredible -- the devastating effect it had on this team of hardened detectives. My own daughter was the same age at the time and it was just the most terrible thing.”

In Musselburgh Black worked as a lifeguard. Twenty years later Caroline Hogg would disappear close to those same pools.

When he turned 15, Black moved west again, to Greenock.

A year later, in 1963, he faced the courts for the first time after molesting a seven-year-old girl in an abandoned air raid shelter.He had lured her from a swing park with the promise of showing her a box of kittens. Instead he choked her to within an inch of her life and then violated her. Yet he was not incarcerated for the crime, receiving only a caution for lewd and libidinous behaviour.

Black relocated back to Falkirk, where he started dating his one and only girlfriend. They stayed together for a while and Black even asked her to marry him. She said no and the relationship ended acrimoniously.

In 1966, while working as a builder back in Kinlochleven, he was reported for abusing the daughter of a couple he was lodging with.

In 1967 he was found guilty of three counts of indecent assault and sent to borstal in Polmont for a year.

“I did not like getting locked up and vowed I’d never get locked up again,” he later told police.

Black moved to London on his release and soon became immersed in child pornography.

Again he found work as a swimming pool attendant, where he could earn money while spying on young girls in their costumes.

Swimsuits were one of the paedophile’s particular fetishes, and behind the locked door of his rented room in north London he would squeeze himself into young girls’ costumes and act out sordid sex acts.

A one-piece suit found in his van when he was finally captured in Stow in 1990 was sized to fit ages eight to 10.

He travelled to Copenhagen and then to Amsterdam to buy child pornography.

He also obtained his driving licence, enabling him to secure a job with Poster, Dispatch and Storage, a London-based delivery firm, in 1976.

The back of his van became a lair where he would abuse himself and his victims with a vile stash of crudely-fashioned instruments.

A delivery run took him past Coldstream in 1982 when he snatched Susan Maxwell, back to Portobello a year later when he stole Caroline Hogg from the promenade, and through Leeds in 1986 where he abducted Sarah Harper.

Black went to Northern Ireland in August 1981 to deliver posters, and it was there he murdered Jennifer Cardy.

Ultimately the receipts relating to this delivery trip proved his undoing.