I don't understand why you think that criminal record checks, mental health checks, etc. would make people who own guns into "career criminals".
As brianchu pointed out, the Virginia tech shooter was involuntarily detained because of mental illness about 15 months before he bought his guns. He then killed 32 people with them. Would prohibiting a law prohibiting people like Seung-Hui Cho from buying guns for a few years really be a step along the road to tyranny?
More to the point, how is it that 15 months after being involuntarily committed Cho was worse than he started? That sounds a lot more like a failure of the mental health system than a lack of proper gun control.
The anti-gun myth implicitly assumes that if you have someone who, given access to guns, would shoot a bunch of people, but you take those guns away, that person suddenly becomes harmless. I don't want anyone like that walking around free in society; I don't want them buying guns, and I don't want them driving cars or buying anything at hardware stores or pool supply stores. They're a clear danger to themselves and to others. However, I'm not going to support gun control measures just because the mental health system isn't perfect.
Adding regulations that restrict what free people can do or buy based on their past history doesn't tend to be very effective. Ex-cons who are disqualified from owning guns, and who cannot buy them legally, have no trouble acquiring firearms through other means.
>More to the point, how is it that 15 months after being involuntarily committed Cho was worse than he started? That sounds a lot more like a failure of the mental health system than a lack of proper gun control.
Treatment for mental problems isn't an exact science. It may be that he would have been worse had he not been committed. Personally I don't want more restrictions on guns, but I find the argument that the mental health system is the point of failure in these kinds of crimes to be pretty unpersuasive.
As brianchu pointed out, the Virginia tech shooter was involuntarily detained because of mental illness about 15 months before he bought his guns. He then killed 32 people with them. Would prohibiting a law prohibiting people like Seung-Hui Cho from buying guns for a few years really be a step along the road to tyranny?