New York inmate's golf drawings lead to exoneration in murder

Mr Dixon said multiple witnesses could have testified he did not fire the gun.

But his trial lawyer did not call any of them as several had been accused of perjury.

Unusually, the investigating homicide detective did not testify during the trial either.

But a more serious flaw in the case was uncovered by Georgetown University's Prisons and Justice Initiative.

Prosecutors had omitted to reveal to Mr Dixon's defence attorney that a gunpowder test on his client's clothes had come back negative.