The next time a cop stops you get three feet in front of him, jump at him, start screaming at him and then through a big container of popcorn in his face all at the same time and see just how many times he shoots you.
Do your own links and tell us who witnessed this, other than you and your gun porn fantasy playing inside your own head.
If personal insults and attacks is all you can come up with then you have nothing.
I have read the news stories, there is nothing there about him leaving the building or going to get a firearm. People who carry, carry all the time. I know this to be true of most retired LE. I have carried a firearm for a living while involved in Law Enforcement. The reality that you may come in contact with someone who wants to "even a score" are not confined to just while you are on duty or before they retire. There is a reason that there is a law that allows retired LE to carry concealed nationwide.
I have not patted this shooter on the back or said that what he did was right. I have said that there are other factors involved. Some are indicating that because he objected to another person using their cell at the theater or his being blunt with a neighbor somehow make him guilty. That is BS. He may be a little cranky and not like people breaking the rules but that does not make him a killer.