Photos: Picking a face in the crowd

San Francisco start-up 3VR Security's technology breaks up the footage into key scenes and creates an index of searchable thumbnails. Once it has labeled a person, the software's facial-recognition engine will pull up other scenes featuring that individual or similar-looking people.

This screen capture shows the results of a search on 3VR employee Michael Pittman's face. It picked out the six times he passed cameras that day.