Special Codex News Today

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. theyre 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 didnt see a time stamp, but you found on...

The surveillance video. the first thing the attorneys and the family were concerned about, they didnt see a time stamp, and you found one. >> yes. >> reporter: how? >> well, the time stamp is in another stream of video. so you have to be able to access it using special codex. you have to pretty much know where to find it, but its there. once the time stamp is located you can then begin to make sense of it and begin to track people. >> reporter: by piecing together the time codes, fredericks team...

Video. >> the first thing the attorneys and the family were concerned about, the didnt see a time stamp but you found one. >> yes. >> how? >> the time stamp is in another stream of video. so you have to be able to access it using special codex. you have to know where to find it but its there. once the time stamp is located you can then begin to make sense of it and begin to track people. >> by piecing together the time codes, frederiks team found more than 18 minutes of surveillance showing kend...