Some days, Peter Tobin came into court almost jauntily, as if settling down for a day's entertainment. On others he shuffled, as if wearing slippers that were too big. A small, insignificant-looking man, sandwiched between two burly security guards, he nevertheless had the air of someone who knew that he was pulling the strings.

Which, in a way, he was. By denying his guilt in the teeth of damning scientific evidence to the contrary, he was in control. Tobin clearly relished starring in his own elaborate drama, sticking up two fingers to the authorities.

The whole trial, in that sense, was a game of his own making. Sitting in the dock wasting public money and listening to his defence counsel defend his reputation represented better entertainment for him than hours locked in a cell in Peterhead prison.

Every day he arrived in court wearing either a baby blue or mauve pullover - pastel shades to soften his image and match his silver hair. His fringe was too long, which gave him a seedy look. He often scribbled notes to his defence, participating in the charade of indignant innocence.

A picture emerged during the trial of an itinerant, uneducated, rootless man, living off invalidity benefits, who bought and sold old cars at auction. For years, it appeared, he had lived on prescription drugs - amiltriptyline, an antidepressant, and diazepam, a sedative. All he was good at, it seemed, was digging holes.

What also emerged was the poverty of his relationships with other people. He told detectives he had few close friends - he struggled to remember the names of just two - and he said he was not close to his children. “Once you get married and split, that's it like.” His father, he said, was an “****hole”. He referred to women in the crudest terms. “She was a poke and that was it, end of story.”

It is of course his deranged and brutal relationships with women that are central to understanding him.

The women he preyed on were always much younger than him, and, like Vicky Hamilton, usually trusting or vulnerable. He appeared to be able to turn on the charm until he had them in his clutches.

His first marriage was to a 17-year-old Glaswegian called Margaret Mackintosh, when he was 23. She has spoken of the terrible abuse he inflicted on her and how he bought her a puppy, which he decapitated because it was barking.

Cathy Wilson, who married him and lived briefly with him in Bathgate until she could stand his vicious rages no more, was only 16 when they met. He was 41 and at first wooed her with kindliness and attentiveness.

The schoolgirls whom he drugged and raped in 1993 were aged 14 and 15.

Vicky was also 15 when she met him and believed him to be a middle-aged good Samaritan on a snowy night.

Another manifestation of Tobin's inadequacy and attention-seeking is to be found in his health. There was a suicide attempt by overdose after Cathy left him; and he has faked several heart attacks. The trial in Dundee was delayed one morning while a doctor was called to attend to him.

Tobin was heard on tape earnestly listing his ailments to detectives: he had cardiovascular heart disease, something wrong with his leg, a bad back and had had a kidney operation.

Officers who have had contact with him believe he is a deeply egotistical person who relishes the limelight.

Tobin did not take the witness stand, and one of the fascinating episodes of the lengthy court case was the chance to hear him speak for the first time on video. He was barely articulate, at times wheedling and crafty, at other times sullen and aggressive.

As one detective put it, the really dangerous ones are always the most insignificant-looking.

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