Dad remembers slain aide as friendly, steady, kind

This February, 2010 photo provided by the office of Rep. Gabrielle Giffords shows aide Gabe Zimmerman, center. Zimmerman, 30, was killed Saturday, Jan. 8, 2011 when a gunman opened fire at a political event with Rep. Giffords in Tucson, Ariz. (AP Photo/Office of Rep. Gabrielle Giffords)