As a retired federal agent, I was concerned with Alison Hopper's letter today regarding the Aurora shooting. Alison calls for a ban on all assault weapons to prevent future mass shootings. All assault weapons (selective fire for both semi-automatic and full automatic fire) have been controlled since the 1934 Federal National Firearms Act. I believe she was referring to the semi-automatic arm used by the Aurora shooter. I would ask how a ban would prevent any mass shooter?