CNN CNN Saturday Morning November 23, 2013 15:40:00
Department of justice, and a contract instructor at the fbi academy in quantico. we are here to get an answer. has this surveillance footage been altered? >> those files are not original files. they're not something that an investigator should rely on for the truth of the video. >> reporter: cnn hired fredericks' company, forensic video solutions, to analyze the surveillance video. the first thing that the attorneys and the family were concerned about, they didn't see a time stamp, but you found one. >> yes. >> reporter: how? >> the timestamp is in another stream of video, so you have to be ab...