What would Kant do?

In the spring of 2012 a man named George Zimmerman shot and killed a teenager named Travon Martin; this case has sparked fierce emotion and irrationality among those involved and throughout the country in general. I'm taking this time to discuss this within the framework of Kant because, among other reasons, it's the perfect opportunity to do so. The legislators in Florida, prior to this killing created a bill called the "Castle doctrine" which allows any citizen to apply deadly force to anyone who is an immediate, or perceived to be an immediate threat to their person. Kants' theory of Universal law states that for an action to be law it has to be followed all the time, by everyone, without exception. If we agree as a society that murder is wrong, then do the circumstances of the act really matter? Would the perceived racial element here actually matter, (Zimmerman is Latino, Martin was Black)? Kant also tells us that consequences are irrelevant, and that the "greater good" is also irrelevant, but rather the ends can and do justify the means provided the intent was good in and of itself. If Mr. Zimmerman had shot and killed Mr. Martin for the purpose of saving society from financial burden, or to prevent Mr. martin from committing future crimes, or an immediate one, under Kants' ethics, this would be an act of Duty.

So there it is, the synopsis of Kant, and how he defines a justifiable act, verses an indefensible one. Would we, as a society really condone anyone killing, at anytime, for any reason? Is there ever a "good" reason to kill? For Kant, if it's ok to do it once, regardless of the circumstances, then it's ok for everyone to do it anytime, for any reason. People continuously take the position that there are "always exceptions to the rules" always "what ifs" that can't be perceived, but if we could all adopt a life of rationality and reason vs. self-loathing and disassociation with responsibility, wouldn't the world at large be a better place?

http://www.opednews.com/articles/On-The-National-Outrage-Ov-by-Sherwood-Ross-120331-450.html