A judge also sentenced Jon Bartlett, 36, to three years supervision and ordered him to pay $16,365 (€11,103) in restitution.
Bartlett was convicted with two other former officers of taking part in the beating of Frank Jude Jr. outside a party in 2004.
The other two former officers, Daniel Masarik, 27, and Andrew Spengler, 28, were scheduled to be sentenced later Thursday.
A federal jury determined in July that the three violated Jude's civil rights and conspired to assault him while acting as officers. Officer Ryan Packard was acquitted of federal charges.
Jude, 29, said the confrontation began as he was leaving the party, when a group of men surrounded his truck and dragged him out, accusing him of taking Spengler's police badge.
He said the attackers kicked and punched him, put a knife to his throat and jammed a pen in his ears as he begged for mercy. Jude said he heard Spengler call him a racial slur.
No badge was ever found.
"They came close to killing Mr. Jude," said his attorney, Jonathan Safran. "They caused him serious permanent physical injuries and mental injuries he and his family will have to deal with the rest of their lives."