Giffords to mark shooting anniversary with vigil TUCSON, Ariz. - Rep. Gabrielle Giffords plans to attend an Arizona candlelight vigil exactly one year after she and 18 others were shot outside a Tucson grocery store during a congressional meet-and-greet. Giffords husband, former astronaut Mark Kelly, will be one of the speakers at Sunday evening's vigil, which will be held at the University of Arizona. Giffords' spokesman Mark Kimble says the congresswoman will not grant any interviews while she's in Tucson. The event is designed to honour those who survived and to remember the six people who were killed in the Jan. 8, 2011, shooting. Giffords was shot in the head during the rampage. She has been undergoing physical and speech therapy for the past year in Houston. Meanwhile, a trailhead named in honor of murdered congressional aide Gabe Zimmerman was dedicated Wednesday near Tucson. The public was invited to attend the ceremony establishing the Gabe Zimmerman Davidson Canyon Trailhead. The 30-year-old Zimmerman served as an aide to U.S. Rep. Gabrielle Giffords. Zimmerman was killed along with five others in the Jan. 8, 2011 Tucson shootings that injured Giffords and a dozen others. KVOA-TV reports The Pima County Board of Supervisors renamed the Davidson Canyon trailhead in February at the request of The Arizona Trail Association, of which Zimmerman was a member. Zimmerman was an avid hiker and runner and helped obtain the National Scenic Trail designation for the Arizona Trail, an 817-mile path from Mexico to Utah that was completed this month.