According to the rather vague details reported by the local NPR affiliate, KJZZ, which is reliably unreliable on firearms issues and crime reporting, and which usually just parrots other media outlets on such matters, the shooting occurred at some sort of "office" building, not in Glendale, but in Phoenix, near 16th St. and Glendale Ave. A civilian witness reportedly followed the shooter's (?) vehicle to a residence somewhere in Phoenix, which was then surrounded by Phoenix PD ... details were sketchy. Today, it's reported that a vehicle matching the description of the alleged shooter's was found in "central Mesa", which would place it near my home, along with the body of a 70 year old man who matches in some way(s) the alleged shooter's description, apparently dead of a self-inflicted gunshot, again, according to second-hand reports... In any event, this seems to have arisen from some sort of business dispute, not a random "mass murder" massacre, as I gather it was suggested to be by Mark Kelly, the husband of brain-damaged former Congresswoman Gabriel Giffords, who herself is an admitted owner of a high capacity magazine Glock pistol, who was at the time of the incident beseeching congress to ban such inanimate objects, using the tiresome and dog-eared "for the children" refrain.
In the interest of "full disclosure", I'm a "sustaining member" of KJZZ, which for all it's faults, and the built-in-bias of NPR national news, is still the local gold standard for broadcast news, arts, cultural, and etc. reporting, as well as sophisticated musical and comedy shows, placing it orders of magnitude above the brain-dead drivel offered by local private broadcasters, which could be used to torture Taliban prisoners, or Americans...