Why did Jaycee get left in hell for so long?

There are many mysteries clouding the abduction and suffering of Jaycee Lee Dugard, but this weekend there were some that just would not go away. They buzzed and disturbed without resolve.

How did Phillip Craig Garrido, a serious offender and known addict of sex with violence, manage for 18 years to hold on his property undetected a girl who became, in time, a woman with children? How could a man visited regularly by parole officers, overlooked by neighbours, and whose behaviour regularly aroused suspicion be undiscovered for so long? How could a convicted sex offender take alarmingly catatonic young girls to community events and go unquestioned? How could a police officer investigate neighbours' concerns and come away having warned Garrido only that he was in breach of garden by-laws?

These, and more, are the questions that are being asked in the Californian town of Antioch, where the saga was played out, and concluded last week with Garrido's arrest and Jaycee's liberty. They are being asked in South Lake Tahoe, the suburb from where Jaycee, as an 11-year-old, was torn from normality. And, increasingly, they are being asked in the police stations, and the offices of the authorities whose supervision of Garrido was so obviously lax.

To try for some understanding, we have to go back to the origins of the story. The ironies and happenstances that led to the abduction of Jaycee Lee Dugard began in September 1990 when Carl and Terry Probyn decided to move their family out of their home in a secured building in Orange County. They were fed up with the noise and the crime and wanted a quieter, more rural place to raise their daughters, Jaycee, 11, and baby Shayna. Somewhere, Carl explained, where he and his wife would not have to run Jaycee to school by car every day; a place where she could go safely by herself.

They found their idyll in the north of the state, at South Lake Tahoe, a sleepy suburb of the lakeside resort, and they moved into tree-lined Washoan Boulevard. The air was good, crime almost non-existent, and Jaycee walked or took a bus to school. And so, 10 June 1991 seemed just another day in South Lake Tahoe. Jaycee got dressed for school, left the house in her pink windcheater, pink slacks and white sneakers, and went to the bus stop across the street. Carl, her stepfather, was working in the garage, and he noticed a car slow down as it passed the bus stop. He thought it must be someone who needed directions. All of a sudden, it did a U-turn, braked by the bus stop, and a woman's arms reached out and yanked a screaming Jaycee inside. With his car keys in the house, Mr Probyn leapt on his mountain bike and pedalled after the car, which accelerated away. It was a grey Ford or Mercury. He didn't get its number.

Police were on the scene swiftly. But for all their work (5,375 people were interviewed), and the national coverage of the abduction (it was the Madeleine McCann story of its day), there was just one suspected sighting before the trail went cold. Rewards were offered, monies donated, and the Probyns – who fell under suspicion – began a remarkable campaign, run out of their home, to find Jaycee. Over the next year, they would send out over a million posters bearing her open, Huckleberry Finn features.

There was no fruitful response. The reason was that, before dawn the day after she was seized, Jaycee had been squirrelled away on a property, 124 miles south west, owned by her abductors, Phillip and Nancy Garrido. She was to remain there, hidden, abused and shorn perhaps of any will, for the next 18 years.

Garrido was the instigator, his wife, by all accounts, the submissive dupe. Now 58, he stands 6ft 4in, and had been convicted of a sex offence so serious that he was the subject of lifetime parole, and wore a GPS ankle tag. In 1976, he had kidnapped a 25-year-old casino worker in South Lake Tahoe, handcuffed her, and taken her to a small warehouse which, with its spotlight, carpet-lined walls, sex aids and pornography, was a hellhole straight out of Prime Suspect.

Garrido was sentenced to 50 years for abduction and rape. He served only 10 years, despite telling police officers that he could only achieve sexual satisfaction by applying violence. There is thus little room for doubt about his motive for capturing an 11-year-old girl. She was, with his wife's consent, his plaything. When Jaycee was 14, she gave birth to a baby girl; four years later another followed. Both were fathered, if that isn't too absurd a word for such grotesque circumstances, by Garrido. No doctor ever attended them, either at their birth, or subsequently.

This warped household was at 1554 Walnut Avenue, a name which suggests mock-Tudor cosiness, but, in reality, is a scruffy street on the outskirts of a blue-collar city. Here, the wire fences, pick-up trucks and satellite dishes are often more imposing than the ramshackle homes. The basic geography of the Garrido plot is now known. At the back and side of the single-storey house is a substantial yard. In this, and behind thick shrubs and a six-foot fence, is a compound containing two tents, and a pair of sheds, neither of them more than 10ft by 10ft. One is sound-proofed and could be opened only from the outside. This area – entered by lifting a small, narrow piece of tarpaulin – was where Jaycee, and later her daughters, were largely confined.

To parole officers, who made regular visits, they were effectively invisible. But not to to the neighbourhood, thanks to "Megan's Law", which makes public the whereabouts of sex offenders. Kids on the block called Garrido "Creepy Phil". Several neighbours had expressed disquiet about the children they heard or saw in his yard, and one went further.

In 2006, police received a call from Walnut Avenue that there were people living in tents on the property, that they included children, and that Garrido was "psychotic and had a sex addiction". A police officer visited, did not search the yard, and, staggeringly, merely warned Garrido that living outside was against neighbourhood ordinances. The shouts of playing children could not have been a more misleading guide to what had happened inside the Garrido property. The bare, legalistic bones of the charges against him – kidnapping a child under 14, kidnapping for sexual purposes, false imprisonment by violence, six counts of forcible rape, and seven counts each of a "forcible lewd act on a child" – are all any but a voyeur needs to know. Jaycee, according to her stepfather, never told her daughters – named Starlite and Angel – that she had been kidnapped.

Some sort of rough early draft of Garrido's personal history is now emerging. Born in 1951, he was a musician, who developed, according to relatives, a serious LSD habit that permanently addled his mind. Music had long since been left behind, and for some time he had run a small printing operation, doing business cards and the like. In latter years, Jaycee acted as designer for the printworks, talking with, emailing and even occasionally meeting clients. The business, not listed in local directories, would have brought in not much more than pin-money, and so it is a mystery where the cash to sustain five mouths came from.

Perhaps more puzzling still is the role of Nancy Garrido. A niece of a fellow prisoner, she met Garrido as he served his rape sentence at a federal penitentiary at Leavenworth, Kansas, and married him while he was still in jail. She participated in the kidnap, kept the secret, and did more. In 1993, Garrido served five months in jail for breach of parole, during the entirety of which his wife kept Jaycee confined, and made no move to alert anyone to the presence of the girl, then aged 13. She, too, has been charged. Like her husband, she pleads not guilty.

But, in recent years, Garrido began to get religion in a way that he had once got sex with violence. Neighbours reported hearing what sounded like religious meetings going on at his property (an eventuality that does not cause the alarm in the US that it might in, say, Maidenhead). These, it seems, were rituals conducted by his own church, known as God's Desire, of which there were about six adherents. Last year, he started a blog, a measure of whose insanity is that the opening paragraph ("... the Creator has given me the ability to speak in the tongue of angels...") is much the most rational part of it. And it was religion that, finally, was to prove Phillip Garrido's undoing.

In recent times, he had appeared more and more in public with his two daughters in tow. It is not known how he explained them to his clients when he took the girls, but at least one person was told he was babysitting them for a neighbour – an unusual task to entrust to a sex offender. At other times, he told people they were his daughters, most recently at a birthday party at a community centre, where one attendee, Chevonne Molino, said the older girl seemed unable to cross the room without asking Garrido: "Dad, is it OK if I go here?"

On Tuesday, Garrido had taken them to help distribute religious tracts at the University of California, Berkeley. A sharp campus security officer called Ally Jacobs felt his behaviour with the girls was strange. They were pale, not in school, and acted as if they were brainwashed. She said: "The younger daughter was staring directly at me, as if she was looking into my soul, with this eerie smile on her face." She checked his identity, saw he was a registered sex offender, and notified his parole officer. Garrido was called in to explain himself. Whether through arrogance, or that sub-conscious desire to be found out that can overtake long-time abductors, Garrido brought with him both his daughters, now aged 15 and 11, and also their mother, the little girl he had captured 18 years before, now a 29-year-old woman going under the name of Alissa. Her real identity was soon established, and Garrido and wife arrested.

Back in South Lake Tahoe around 4pm that day, Terry Probyn – now divorced from Carl, partly due to the strains caused by Jaycee's disappearance – was at work. Her phone rang. It was a police officer telling her that the daughter she had last seen as a child had been found alive. Terry took some persuading it was not a hoax. Overjoyed, she hurried to a reunion, where Jaycee greeted her with the words: "Hi, Mom. I've got babies."

This took place in a motel near San Francisco, where, with therapists, the two women, plus the daughters and sister Shayna remain still. Neither Jaycee nor her mother has spoken publicly, but Carl Probyn said Jaycee still looks young, and added: "Her education stopped at fifth grade ... in a way, she's still 11." He also said that Jaycee feels guilty for bonding with Garrido. "Jaycee has strong feelings with this guy. She really feels it's almost like a marriage." The extent of this bond has yet to be detailed, but any shame would not be hers; for a dependency to develop in these circumstances, however perverted its origins, is common.

For all the parallels that have been drawn between Jaycee's case and those of Elisabeth Fritzl and Natascha Kampusch in Europe, there is another which may be a better point of reference. This is the "Girl in the Box" case, dating from 1977, when an ill-educated timber worker called Cameron Hooker kidnapped (with his wife and baby in attendance) a 21-year-old Oregon woman known to the court as "Colleen Stan". He was an S&M obsessive and subjected her to horrific treatment, including fitting her head with a box that excluded all light, making her live for the large part of seven years in a wooden cage he had built, and raping her.

Despite certain freedoms (she was, sometimes, allowed to go jogging and, in the latter part of her confinement, even permitted to take a job as a cleaner at a local motel), she had had her will broken and become so utterly dependent on Hooker (for food, drink, even the right to wash) that she made no attempt to escape. More than that, even though she was treated by Hooker and his wife as a slave, she developed a relationship with Hooker that prompted her to write what were described in court as love letters. For all this, he was convicted and is now serving a life sentence. The case remains a demonstration of how a determined psychopath can so break the will of their prisoner that they make no attempt to escape.

The other mysteries of how a sex criminal like Phillip Garrido was able to indulge, undetected and unquestioned, his worst fantasies for 18 long years, will take a lot longer to answer.