As to whether or not the news media would report a Concealed Carrier taking out the suspect, don't bet on it being reported, even if it happened. School shooters have been stopped by armed students and staff. News reports only said, "Staff convinced him to put down the gun." They neglected to mention, "when that staff member (or student) pointed their own firearm at the useless piece of cowardly trash."
A legally carrying gun owner stopping a criminal is not part of the Anti Agenda, and thus not newsworthy.
And since reports are that no police discharged their guns, it was a suicide or other way the BG was stopped.
Once again, the police arrived in time to write reports, not save lives. Anyone who thinks the police will save them is living in LaLa Land.