How valuable are background checks? Why does a person purchase a gun? Well, among the reasons, one is to committ a crime. If you are a felon, it makes little sense to purchase a gun that requires a background check if your intention is to committ a crime. If you are mentally ill, it is statistically unlikely that you have been adjudicated as such by a court. Thus, it is just unlikely that there is an accessible record of your illness. So, to the extent that background checks would seem to preclude some felons and mentally ill persons from legally obtaining firearms, they are valuable, but they are no panacea.