Digging begins

At least 30 British policemen begin clearing and digging operations in an area of scrub land about a five-minute walk from the apartment where the child disappeared.  Sniffer dogs and a team of forensic archaeologists are also at the site.  An expert describes the ground-penetrating radar that will be used:

The radar uses electromagnetic waves that are fired into the subsurface at a pretty rapid rate and we measure what comes back from those signals.  If you have got a buried object that is sufficiently different, with different properties from the surrounding area, it will show up very, very clearly; whereas if you have got a gradual change it can be difficult to detect.