http://www.securitypark.co.uk/article.asp?articleid=26106&CategoryID=1
"Cambridge Consultants have launched prism 200, a compact 'through-wall' radar sensing device which gives security forces a means of reducing the risks involved in tactical entry, and siege or hostage situations.The product, which is the size of a briefcase and can be carried and used with one hand, employs sophisticated software to evaluate the position and movement of people in rooms and buildings."