At 2:00 a.m. on Saturday—about eight hours before he allegedly killed six people and wounded 14, including Rep. Gabrielle Giffords (D-Ariz.), in Tucson—Jared Lee Loughner phoned an old and close friend with whom he had gone to high school and college. The friend, Bryce Tierney, was up late watching TV, but he didn't answer the call. When he later checked his voice mail, he heard a simple message from Loughner: "Hey man, it's Jared. Me and you had good times. Peace out. Later." That was it. But later in the day, when Tierney first heard about the Tucson massacre, he...