vaughan thought it was a drill. drill started, she texted her husband mark. she walked to a window nearby and filmed video as lawn enforcement sprinted toward the building. oh, that is scary said a voice calmly in the background. they're all geared up, rifles and everything. in the background somebody laughs, they still didn't know. then the reality set in. she texted her husband again, a second time quoting, well, it's real. and then a few minutes later, another message quote, we're locked in an office, mark vaughan said he told his wife to stay calm and not to panic. all of that and they said they trained for this. they know it's going to happen. let's listen, kttv fox 11, los angeles. >> they are capable or they're capabilities of, they can, they can sniff out the ballistic explosive content within shell casings, also residue that's left on firearms. so this is just a for example. but if maybe one of the suspects were scene, identified. but the gun wasn't recovered, we would bring one of our explosive detection canines in. and have the canine run the track