Jack Martin 
Brother, Can You Spare a Dime? [EPUB ebook] 

When President Franklin Delano Roosevelt’s life is threatened, FBI Director Hoover has no choice but to dispatch Agent Harry Bierce, the one man he can trust to stop an assassination. Problem is, Bierce is no ordinary agent. With no verifiable history, Hoover has no way to control him or his methods. Preferring to work alone and wanting no acknowledgement for his part in solving high-profile crimes, Bierce often single-handedly brings criminals to justice when other agents have failed. But when his search for the assassin leads him into a web of corruption, he comes up against local law enforcement who want to protect their reputations and federal agents who want revenge, no matter what the stakes.