I know who really gets pissed after one of these school shootings.
Since the long black trenchcoat has become the symbol for gun-toting angsty youth, sales of this item would be tricky. There must be the boom years - After Underworld came out, I'm sure there were tons of hot chicks looking for trenchcoats. Same with the Matrix films. But all it takes is one whacked out fucker to get a gun and start using it, and all those sales are gone.
And it's not even your fault.
What can you do when the product you design and sell happens to not only keep you warm and dry, but is able to conceal extremely large automatic weapons? Do you shorten it up, and lose all the sales once people's knees start getting wet?
I think that you should have two options when purchasing a trenchcoat. For one, if it's brown or beige, I think you should get a discount. However, to buy the black ones you should have to pass some sort of rigorous mental test, designed to weed out the crazies. If you fail the test, you can still buy the jacket - but it has "Possible Gun-Happy Freak" in large white letters on the back.
I'm sure that by taking the pro-active approach the industry can hope to avoid any backlash after the next incident. Hopefully that never happens again, but if it does, maybe the uniform will have changed. (It would be easier to spot the nutjobs if they all wore pink tutus.)