In cases of child abduction, one of the most important assets the police can call upon is the media.
Detectives from Cambridgeshire Police fully appreciate the crucial role which newspapers, television and radio can have in securing a breakthrough. For this reason, an orchestrated press operation has been in action during the past week.
The principal role the media can play in solving crimes is in jogging people's memories or consciences to obtain a vital tip-off. While brilliant detective work may solve the mystery of what has happened to Jessica Chapman and Holly Wells, the key is more likely to lie with a neighbour who has noticed something strange about the behaviour of the single man living next door, or the motorist who remembers seeing a van parked at a lay-by.
As well as direct appeals to the public for help, the police use the media in more subtle ways to communicate with the public and kidnappers, often prompted by information given to them by criminal profilers.
A dramatic illustration of the different tactics was shown on Thursday when the police appealed directly to an abductor in an attempt to stir his or her conscience, emphasising that choices were available, and to reinforce the idea that the children are individuals.
For its part, the media is happy to provide a useful public service, providing it gets the access and information it needs to tell the story and the pictures with which to illustrate it graphically.
In the past week, we have seen the police in Soham try to carry out a classic "story-a-day" approach to the suspected abduction to ensure it stays at the top of the news agenda.
Having failed to find any clues to the girls' disappearance during overnight searches last Sunday, the police held a press conference on Monday afternoon with the parents. The use of relatives to generate publicity is usually withheld for a couple of days but the police must have realised that it was vital to get the maximum amount of media attention at as early a stage as possible to try to flush out witnesses. The first 24 hours in any investigation are almost always the most vital – that is when the police are most likely to obtain the best clues or crack the case.
The parents of Holly and Jessica have been used throughout. Deeply distressing this may be but they provide a valuable focal point. Pictures of weeping parents have far more impact than a sober-suited policeman. They also provide television news and press photographers with strong images and journalists with quotes.
Throughout most of the inquiry the police have held a morning news conference, at about 10am, and an afternoon one, at 5pm, which gives the media a chance to update their stories and provide headlines for the main news bulletins.
Each day, the police have offered a fresh news item, which not only keeps the story running, but can help with specific lines of investigation. However, after a week, the inquiry is struggling to come up with significant developments.
The media's desperation for a new angle, though, can lead to developments being blown out of proportion. For example, the police searched a white van, but despite briefing journalists that this was not a significant development, many organisations reported it as though it were a major breakthrough.
Cambridgeshire Police have also queried newspapers offering rewards – the Daily Express and the Daily Star have put up a £1m bounty – as this could encourage crackpots and irrelevant reports.
How the news has been released
Sunday 4 August 8.30pm Alarm raised as the girls go missing.
Monday Police issue a public appeal. The girls' parents appear at a press conference.
Tuesday Possible sighting of the girls. David Beckham issues appeal.
Wednesday Chief investigating officer says girls 'probably' abducted. Photographs of girls in football shirts released.
Thursday CCTV pictures of girls walking around Soham released. Police make direct appeal to suspected kidnapper.
Friday Pictures of Jessica on holiday released. Police emphasise that they believe the girls are still alive.
Saturday Reconstruction of the girls' movements last Sunday.
Yesterday Searches widened.