John McCarthy Roll (February 8, 1947 – January 8, 2011) was a United States District Judge who served on the United States District Court for the District of Arizona from 1991 until his assassination in 2011, and as chief judge of that court from 2006 to 2011. With degrees from the University of Arizona College of Law and University of Virginia School of Law, Roll began his career as a court bailiff in Arizona and became an assistant city attorney of Tucson, Arizona in 1973. Later that year, Roll became a deputy county attorney for Pima County, Arizona until 1980, when he began serving as an Assistant United States Attorney for seven years. President George H. W. Bush appointed Roll to a federal judge seat in Arizona after Roll served four years as a state judge.