How about direct ATF to prosecute people that buy guns illegally? And those that commit perjury on background check? Focus on illegal gun buyers first. Next, figure out how to address mentally ill, who kill with knife, gun, or whatever they have present? Third, look at the ZIP Codes with highest rate of violence and figure out how to address that. Thus, leave the other 99% of Americans alone.
Abolish the ATF. No gun is illegal.