barricade situation where it is just the shooter. barricade situation with just the shooter, you're going to as art roderick pointed out, you form a perimeter. you do what we call contain, negotiate. no need to put more in harm's way if there aren't more victims to be harmed. barricaded subject with hostages raises the ante. will they continue to kill people or are they holding to them as human currency to negotiate with authorities. thirdly, the active shooter that we have to, law enforcement officers are brave individuals, men and women that are swearing out to that mission are to respond to sound of the guns, go to the threat, take the threat out. >> and sam, you have all of that met with urgency of trying to care for any who may be injured because this is also a critical time in which to tend to any potential injuries. >> exactly. if there was an assault rifle used, you can imagine people are