Surveillance video changing how police catch criminals

Delvin Barnes, the man believed to be caught on video abducting a Philadelphia woman, is now on suicide watch at a Virginia jail, where he's facing charges in a different case.

Barnes is accused of abducting Carlesha Freeland Gaither on Sunday night. The whole terrifying incident was caught on video. It's the video that might have saved Freeland-Gaither's life. In it are clues that led police straight to Delvin Barnes.

Surveillance videos like the one used in the Philadelphia abduction case have become one of the best tools police have to catch criminals.

CNN's Kyung Lah has more.