At 9:20 a.m. on June 2, Carey Hal Dyess walked into the converted single-story house that served as Jerrold Shelley’s law office in Yuma, Ariz.

Dyess, 73, instructed an office administrator to move out of the way and then shot and killed the 62-year-old lawyer, who had been in the process of packing up his office and retiring.