A weird relic rested on the bookcase in my family's last home in New Orleans: a wooden pipe that had belonged to Jim Garrison, the Orleans Parish district attorney who tried and failed to convict a local businessman named Clay Shaw for the assassination of President John F. Kennedy. The pipe still smelled of the tobacco its owner had packed and lit before setting it down at a cocktail party. Garrison—that's him on the right—had left the party and forgotten his pipe. And because he was still a hero to some, and especially to my mom, she took Garrison's pipe home as a souvenir.