U.S. District Judge John Roll was killed in the shooting in Tucson, Arizona, Saturday that put Congresswoman Gabrielle Giffords in critical condition and injured 18 in total. Roll, a federal judge in Arizona, was at the center of the contentious immigration debate there. He was the target of hundreds of threats against his family and his life after he allowed a lawsuit filed by illegal immigrants against ranchers to go forward. "They cursed him out, threatened to kill his family, said they'd come and take care of him. They really wanted him dead," a law enforcement official said in 2009. Saturday’s shooting has not been linked to any political motivations. Witnesses say the shooter appeared to be clearly targeting Giffords.