Obviously he lied on the BATF form, which is a crime and makes his possession illegal. Whether or not BATF bothered to or could check on mental is their problem and goes to show that the ‘background’ check is nothing more than liberal feel good bullshite.
Results: This killer in Lafayette passed a background check. The killer at the Charleston church passed a background check. The Colorado movie theater shooter passed a background check. The Tuscon killer passed a background check. The killer at the Navy shipyard passed a background check. The Virginia Tech killer passed a background check.
And the liberal/progressive remedy for all that? Why, universal background checks, of course.
Well then he's in real trouble now.