If we are going to go for a "killer profile";  black males between 15 and 25 living in large cities are the most frequent 'killers' by demographic group.

Those same individuals with prior convictions would be an even tighter demographic.

We already have laws against convicted felons possessing firearms or ammunition, of course.

Those charges are just added to each homicide as they occur.   

Does having those laws prevent those homicides by that demographic?  

Statistically, the answer is "No"!