The last confirmed sighting of the youngster before today remains at 3.10pm on Tuesday, February 19 at her school - Westmoor Juniors.

Shannon had just returned from a swimming trip where she was caught on CCTV leaving Dewsbury Leisure Centre.

Within 24 hours 250 uniformed officers and 60 detectives were involved in the search - 10% of the West Yorkshire police's strength.

But the investigation was hampered from the start by the sheer lack of any clear starting point for detectives and search team to work from.

Witnesses, many of whom were children, were not even clear about which direction Shannon had gone out of the school gates.

Shannon mother, Karen Matthews, 32, raised the alarm at 6.48pm in the evening on that Tuesday.

Mrs Matthews said she had said goodbye to her daughter at 8am that morning as Shannon said to her: "I''ll see you at tea-time, Mum. Love you."

When Shannon did not return at 3.30pm as usual she went out looking for the youngster, trying first her cousins Tyler and Levi's home just a few hundred yards from her house in Moorside Road.

When it became clear Shannon was not at any of her friend's homes, Mrs Matthews dialled 999.

Police eventually released a clip of that frantic and tearful call.

Within hours, more than 200 police were looking for Shannon and neighbours organised their own search parties as temperatures plummeted to minus 7.

By the next morning, West Yorkshire Police's highly respected Homicide and Major Enquiry Team was brought in, emphasising the seriousness with which senior officers viewed the situation.

The next morning, as media crews gathered outside Shannon's semi detached home, friends and family swore the "timid" youngster would never run away.

Later that night Mrs Matthews made the first of a series of emotional appeals for Shannon to be returned.

As more days passed with no sign of Shannon police became more and more convinced they would not find her alive.

Crime statistics show it is almost unheard of for children snatched from the street by a stranger to be returned after three days.

Detective Superintendent Andy Brennan, the experienced officer brought in to lead the inquiry, said: "I couldn't be more concerned."

With no "smoking gun" - a definite suspect, a later sighting or forensic lead - Mr Brennan had no choice but to embark on a painstaking process of searching homes and ruling out suspects.

Every home on Shannon's usual route home was searched by a team of "body dogs" and known paedophiles in the area were all visited.

As is routine, Shannon's own family inevitably came under scrutiny by detectives.

This process was complicated by the complex nature of her family relations.

Mrs Matthews has seven children by five different fathers.

She lives in Moorside Road with her partner, Morrisons fishmonger Craig Meehan, 22, and four of her children - Tony, 11, Shannon, nine, Cameron, five and Courtney, two as well as the family dog Scania. Courtney, who shares a bedroom with Shannon, is also Craig's natural daughter.

Mrs Matthews other three children live with their fathers.

Shannon's natural father, Leon Rose, 29, lives in Kirkheaton, near Huddersfield. He and Mrs Matthews separated more than five years ago.

Shannon's full brother Ian, 10, lives with him.

Mr Rose said he feared Shannon had run away from her mother's to try to find him and after writing on her bedroom wall that she wanted to live with her real father.

All the time the police operation continued unabated with more than half of the UK's body dogs working as part of the operation.

Mr Brennan eventually admitted he feared she may have fallen in the "wrong hands".

With no major lead emerging, even after a fortnight, the spotlight shone brightly on Shannon's family as commentators speculated about the differences between the media coverage of this disappearance and that of Madeleine McCann in Portugal last year.

A number of commentators remarked on the difference between the media coverage of the two missing person inquiries, highlighting the number of stories and amount of cash raised to help the searches.

Some speculated on the class differences between two families as the source of these differences.

Eventually the focus was so intense on Mrs Matthews's family, her partner, Mr Meehan was forced to publicly deny rumours he had anything to do with his step-daughter's disappearance.

In a series of interviews Mrs Matthews said she was convinced her daughter was still alive.

She even had to deny allegations in a Sunday paper from her own parents, that Mr Meehan had hit Shannon.

In an interview earlier this week with BBC Radio Four's Today programme Mrs Matthews again denied rumours about Mr Meehan's involvement and said she believed someone who knew her had snatched her daughter to hurt her.