He states that he understands that such bans will not stop criminals, but I think what he's trying to get at are the individuals such as disgruntled teens stealing their parents guns or rifles and taking them to their school and shooting anything that moves.
He might be thinking of Columbine and such, but the thing is, the large majority of these shootings occur with adults from what I can tell. I'll provide an update with my response when I get a chance, we'll have to see if he can be swayed or not.
The Columbine shooters did not steal their parents' guns, but rather acquired them illegally through straw purchases. Also, the Columbine shooting happened right in the middle of the original AWB. Gun control did nothing to stop Columbine because the shooters violated numerous gun laws before ever firing a shot.
Smith, and Wesson, and Me. -H. Callahan
Well waddaya know, one buwwet weft! -E. Fudd
All bad precedents begin as justifiable measures. -J. Caesar