Officials in Florida on Tuesday took the 'incredibly rare' step of executing two separate death row inmates, a former cop and an 80-year-old man, in a single day.

James Duckett, 68, and Dominick Occhione, 80, were put to death by lethal injection at the Florida State Prison near Starke just hours apart, becoming the 11th and 12th prisoners executed in the state this year alone.

Both men had been convicted of murders dating back to the late 1980s – Duckett was found guilty in the 1987 murder of 11-year-old Teresa McAbee while Occhione was convicted of the murder of his former fiancée's parents.

Duckett, a former police officer who has long maintained his innocence, was the first to be put to death on Tuesday after enjoying a last meal of eggs, grits, bacon, biscuits and chocolate milk, according to the Tampa Bay Times.

He had no last words before officials injected him with a lethal cocktail, and was pronounced dead at 1.19pm.