A select few crazies do not represent gun owners as a whole, and making stricter gun control laws is going to punish lawful gun owners, and that people who really want to murder and break the law are going to do so regardless of how many restrictions are in place.
The NRA estimates that there are between 70 and 80 million legal gun owners in the United States. To compare, there were just over 9,000 firearm homicides in the US in 2009. While anything more than "0" is tragic, the fact is that those numbers come out to be about one tenth of a percent of legal gun owners. That means that about 79,990,000 gun owners are safe, responsible, and have not harmed anyone.
Obviously death is a terrible thing, but there are already plenty of restrictions in place as it is.