A hearing on gun violence began dramatically shortly after 10 a.m., when former Rep. Gabrielle Giffords (D-Ariz.) entered the room alongside her husband, Mark Kelly, and the two senators hosting the forum.

Sens. Patrick J. Leahy (D-Vt.) and Charles Grassley (R-Iowa) escorted Giffords to her seat at the witness table. As she entered the hearing room in the Hart Senate Office Building, members of the audience stood -- a break with normal decorum for a Senate hearing.

Leahy invited Giffords to speak before he and Grassley gave their opening statements, but added, "I expect everyone in this room to be respectful," adding later: "I do not want applause for or against the position that I take or anyone else takes."