Melvin Purvis hunted down America’s most notorious bank robbers, investigated General George S. Patton, questioned Hermann Goering in his cell, and dated Jean Harlow along the way. Born in 1903 in Timmonsville, South Carolina, he was a small town lawyer who wanted to be a diplomat, was rejected, and joined the Bureau of Investigation in 1927 instead. His background check called him honest and ambitious but not brilliant. J. Edgar Hoover scolded him for scoring about 80 percent on the rule books, yet rated him perfect on appearance and loyalty.

That polish made Purvis the face of a Bureau fighting a public relations war against outlaws the Depression public admired. This episode follows him from running the Chicago office by 1932 to a disastrous raid in the Wisconsin woods, the carefully planned ambush of John Dillinger, and a fame so large that Hoover froze him out. His second act took him to Hollywood endorsements, wartime North Africa, and Nuremberg, before a quiet return to South Carolina and a death in 1960 that is still debated.

• At the Little Bohemia Lodge in April 1934, agents in rented cars shot three innocent civilians, killing one, while Dillinger slipped out a back window and Baby Face Nelson killed an agent.
• Anna Sage, facing deportation, set up Dillinger at the Biograph Theater in July 1934, where Purvis signaled his men by lighting a cigar.
• Months later Purvis and his agents cornered Pretty Boy Floyd on an Ohio farm, making him a national hero and a threat to Hoover’s spotlight.
• As an Army provost marshal he chased black market rings stealing roughly 20 percent of supplies in North Africa and investigated Patton’s slapping of hospitalized soldiers in 1943.
• Purvis died of a gunshot wound from the pistol fellow agents gave him at his resignation, ruled a suicide, though a jammed tracer bullet suggests a possible accident.