 Oftentimes they'll use cameras to electronically recreate the scene where they can do it on computers and get a digital image of what it was like in that moment. We also tonight have been talking to John Cohen, former DHS undersecretary and ABC News consultant, and I asked him, did something fail tonight? Well, they will be taking a hard look at the Secret Service and DHS broadly, and I expect the FBI as well will be taking a hard look at the security department