shootings involve people with mental distress. there are other motives, hate, terrorism, revenge. there are all kinds of motives. about 30% involve mental illness. we don't want to stigmatize anybody with mental illness. but sometimes we do see those mental issues arise like in parkland, for example, or in gabrielle giffords shooting in tucson, aurora, these traits manifest themselves to mental illness. then we see guns -- the person in possession of guns. then we see some kind of contact with law enforcement or authorities. i think in the gabrielle giffords case it was maybe with the university police or university authorities. in parkland, certainly it was school resource police and others knew about the shooter there. so you have -- i call it the tragedy triangle.