Judge John Roll lived just a few minutes away from the Safeway on Tuscon, Ariz.’s Oracle Road. So it wouldn’t have been a major inconvenience for him to drop by on Saturday morning to talk business with U.S. Rep. Gabrielle Giffords, who was having an event for constituents at the grocery store.

Roll joined the 20 or 30 people who crowded around Giffords, a three-term Democrat. Just after 10 a.m., a gunman with a 9mm pistol opened fire. Within minutes, six were dead. One of them was Roll, who since 2006 had been the chief judge of the U.S. District Court for the District of Arizona.