What kind of evalutation can ever define you as "safe" to own a firearm?

Contrary to popular belief, Americans don't buy guns for the sake of killing one another, especially immigrants, or for protection from possible daily drive-bys. Each state has their own criteria with which to sell guns. There are also federal laws which prevent the sells of tactical ault weapons. Federal law also instituted the Brady Bill, which a sell is put on a 5-day hold while criminal and/or psychological background checks can be done to determine the suitability of the customer to even own a gun. I think that ault or semi-automatic weapons should be seriously looked at and subsequently banned. Gun owners should be a part of a federal ID ownership bank, along with photographs and fingerprints. On the other hand, the will of an evil or demented person will not stop that individual from potentially killing someone else. Most often they will find ways, even at the expense of their own lives, to carry out their frustrations on the community in form of m murders. These sad events are often times not preventable. Many are undetectable. Gun ownership is largely not abused. But if a potentially dangerous criminal wants to kill, he'll find another proficient way to do it, including homemade bombs.