analysis on the youtube shooting investigation, we reached out to longtime law enforcement expert tony rivera, the former san francisco police chief. nbc bay area's sam brock sat down with him to watch the body cam video and has more from youtube headquarters in san bruno. >> even if it turns out they're stopping dillinger or some big-time criminal, they have to talk to people in a civil way. and those two officers did. >> former san francisco police chief tony rib era is reacting to this encounter. >> hi. are you naseem? >> a startled nasim aghdam woken by police flashlight and facing questions about her state of mind. >> you don't want to hurt yourself, do new. >> we watched the tack taken by police through rib era's eyes. >> anything indicating violence, violence with her parents and violence with anybody -- nothing indicates that. >> reporter: rib era says the starting point for any police officer in this kind of case would be assessing the reason aghdam was deemed at risk. >> why were they reported missing? what were the circumstances? any possible threat. >> reporter: as it stood, the 3