[1] During a night speech by Roosevelt in Miami, Florida, Zangara fired five shots with a handgun he had purchased a couple of days before.

After serving with the Royal Italian Army in the Tyrolean Alps during World War I, he did a variety of menial jobs in his home village before emigrating with his uncle to the United States in 1923.

In his prison memoir, Zangara himself attributed his pain to being forced to do grueling physical labor on his father's farm from an early age.

Arguments have been made that Zangara was mentally ill, incapable of distinguishing right from wrong, and ought to have had an insanity defense presented on his behalf while others have contended that he was sane.

[4][5] On February 15, 1933, Roosevelt was giving an impromptu speech at night from the back of an open car in the Bayfront Park area of Miami, Florida, where Zangara was working the occasional odd job and living off his savings.

[15] A Secret Service agent, Bob Clark, had a grazed hand, possibly caused by the bullet that struck Cermak.

A theory, raised decades later, questioned whether Cermak's death was caused by medical malpractice on the part of the doctors treating him.

[22] Zangara pleaded guilty to the additional murder charge and was sentenced to death by Circuit Court Judge Uly Thompson.

[20] After spending only 10 days on death row, Zangara was executed on March 20, 1933, in Old Sparky, the electric chair at Florida State Prison in Raiford.

[29] The theory is enhanced by numerous researchers, citing their analysis of court testimony, asserting that Cermak had directed an assassination attempt on Nitti less than three months earlier.

[26][30] The conspiracy theorists suggest that Zangara had been an expert marksman in the Italian Army 16 years earlier, who would presumably hit his target,[31] though sidestepping any issues about Zangara's progressive age and health issues since his time in the war, his short stature requiring him to stand on a jostled chair, his experience being with a rifle rather than with a pistol from a great distance, and his own statements regarding his target.

[citation needed] Raymond Moley, who interviewed Zangara, believed he was not part of any larger conspiracy, and that he had intended to kill Roosevelt.

This episode, while depicting Zangara's story throughout, focuses mostly on Nitti's plan to kill Cermak with an initial (fictionalized) attempt in Chicago that is foiled by Eliot Ness and his agents at the end of part one.

Zangara plays a significant role in the background provided for Philip K. Dick's 1962 novel The Man in the High Castle (as well as the subsequent Amazon original series).

This alternate history novel, set after an Axis victory in World War II, bases the point of divergence on the premise that Zangara succeeded in assassinating President-elect Roosevelt on February 15, 1933, in Miami.

Instead of using a small-caliber handgun, Zangara is made into a living cannon or bomb and kills nearly 200 onlookers, including Cermak, and cripples Roosevelt.