In a fractured and chaotic family, the innocent nine-year-old needed her mother to be her protector and guardian. Instead, she was imprisoned as Karen Matthews sought to cash in on her own flesh and blood.

Matthews, apparently an unintelligent and unassuming woman, terrified her daughter, triggered a police investigation which cost nearly £3.2m and also hoodwinked the entire community of Dewsbury.

And all so she, and her accomplice Michael Donovan, could claim a £50,000 reward that had been offered for Shannon's safe return.

This plot was no mere deception. It was a wicked and chilling scheme by Matthews and Donovan to enrich themselves by inflicting suffering on a child.

It involved months of planning before taking a chilling twist in February when the two plotters locked away Shannon for 24 days, imposed on her a rigid set of rules and plied her with the adult sleeping pill temazepam to keep her quiet.

While her daughter's ordeal continued, Karen Matthews, with crocodile tears in her eyes, made a series of heart-rending appeals for help on television having initially phoned 999 to raise the alarm.

This callous woman, who crafted her false words and cunning to echo the genuine anguish of Madeleine McCann's mother, pleaded for help from the people in Dewsbury.

Everyone was taken in. The persistence shown by Matthews as she played the part of a distraught mother was staggering. Support poured in, most notably from the hundreds of local residents who, night and day, helped the police hunt for any clues that might lead them to Shannon.

Meanwhile, Matthews, memorably seen on television clutching her daughter's teddy bear, won the sympathy of a nation.

All those who helped in the search for Shannon will justly feel that they also have been betrayed for sacrificing their time, labour and emotional energy for a mother who could have owned up to her awful crime at any time.

As an abuse of public resources, it was one of the largest ever and this fact must be reflected when Matthews and Donovan
are sentenced.

West Yorkshire Police's vast search for Shannon was the force's biggest investigation since the Yorkshire Ripper manhunt 30 years ago.

It cost more than just money. Officers were taken off other murder and rape cases to join the frantic search.

Even now, it is impossible to know what fate would have befallen Shannon if her captors had evaded detection for longer. As it was, her discovery was marked by an outpouring of emotion from those detectives involved in the case. In later describing Matthews as "a manipulative individual who has demonstrated a remarkable ability to lie", one of those policemen aptly summed up this woman's contradictions.

Even though social services were warned about the family, Shannon's disappearance and complicated family background reveals much about social exclusion in Britain, and the bleak prospects facing those children born into unstable homes and the squalor that Shannon grew up in.

It can only be hoped that society now values its children far more dearly. This is the fundamental lesson that can be learned from this inexplicable case.