When I lived in NorCal, the company I worked for as a carpenter did some work for the Mondavi vinyards. He had an old house on his property that he wanted torn down, but first, he donated the use of it to all the Law enforcement agencies in the area, and finally the Fire Dept who burned it down for him as training.
One day I had to remove some cabinets from the house while the local police were runing some scenario where a husband was holding his wife hostage in the house. They kept bringing in new teams that had no idea what would actually happen, like they had just showed up to a domestic dispute call. At one point I wasn't paying attention and I walked out of the house right into the middle of a confrontation. The looks on the cops faces was great, the were confused and had no idea what to do with this new element thown into the scenario, some random guy carrying a chainsaw. I'm just glad they didn't shoot me, I wasn't wearing the protective gear they all had on.
After that I stood around for awhile watching, I liked the after action analysis discussions. "So why did you shoot him? Why didn't you shoot him?...