Bad People Do Bad Things Regardless of the Law
Gun control laws are justified by making society safer. While the concept sounds good on paper in practice is don't work. The problem comes from the fact that bad people will do bad things. People willing to commit murder are unlikely to be deterred by a law prohibiting them from owning firearms. That's why this news about the suspected perpetrators of the Boston bombing doesn't surprise me:
CAMBRIDGE, Mass. (AP) — A Massachusetts police official say the brothers suspected of bombing the Boston Marathon before having shootouts with authorities didn't have gun permits.
If these people were, in fact, the bombers then it should come as no surprise that they were also in possession of firearms. A person willing to detonate two bombs at a large sporting event isn't going to have a moral issue with acquiring a firearm illegally. The general population of the United States seems to have been suckered into believing that laws will prevent evil men from conducting evil. In reality laws are hindrances only to those willing to obey them. Passing laws against owning equipment after somebody commits a heinous act with that equipment is a worthless gesture, especially when the act itself was already illegal.