Rep. Gabrielle Giffords, left, and her husband, former astronaut Mark Kelly, wave at the start of a memorial vigil remembering the victims and survivors one year after the Arizona congresswoman was wounded in a shooting that killed six others, in this Jan. 8, 2012 file photo taken in Tucson, Ariz. Among those testifying Wednesday Jan. 30, 2013 at the year's first Senate hearing on what lawmakers should do to curb gun violence, will be Mark Kelly, husband of Giffords and a retired astronaut. Giffords, an Arizona Democrat, received a severe head wound in a 2011 shooting as she met with constituents outside a Tucson supermarket. Six people were killed and 12 others wounded. (AP Photo/Matt York, File)