Those frightening images of a masked man on Nancy Guthrie's porch could provide valuable clues to investigators. The FBI already has analyzed the videos from Guthrie's doorbell camera to identify the suspect's backpack. Former criminal investigators say it's almost certain that authorities now are using the footage to build a physical and psychological profile of the suspect in Guthrie's disappearance. The footage released to the public this week totals less than a minute in length. It shows not only the suspect's clothes and shoes, but also the way he moves. Investigators who have worked on high-profile cases say that's all valuable information.