After much informed discussion of William K. Harvey in the comment board, I would say the following:
The claim that Bill Harvey fired a gun in Dealey Plaza is factually unsupported, some would say ludicrious.
Harvey is indubitaly a character in the JFK assassination story. He was fat, agile, intelligent, energetic, and deeply anti-communist. He was a former FBI man and that is important is understanding the mindset he brought to his work as chief of Cuba operations for the CIA in 1962-1963.
Harvey was highly-regarded, and he also attracted suspicion. He felt no obligation to obey the law in pursuit of his duties. He was the CIA’s leading authority on political assassination, and he despised the Kennedy brothers, especially Bob.
John Whitten, a senior CIA official who knew Harvey well, was asked in secret session with congressional investigators, why Harvey might have told his wife to destroy his personal papers after his death.
“He was too young to have assassinated McKinley or Lincoln,” Whiten replied. “It could have been anything.”
That was Bill Harvey, a plausible JFK suspect.
According to the National Archives online JFK data base, the CIA retains a 123-page file on Harvey’s operations. This file is supposed to be made public in October 2017.