State District Judge Mike Wilkinson imposed the sentence after Cooper, 30, changed his plea from not guilty to guilty. A jury convicted him Tuesday of tampering with a government document for altering the car title of one of his wives.
Cooper had requested that the judge assess his penalty instead of the jury, so jurors were excused Tuesday after delivering their verdict.
The jury concluded that Cooper, who has been married at least seven times and was convicted last year of bigamy, signed his name to one wife's car title without permission and forged her father's name on the document.
Jurors heard testimony from four ex-wives and one former girlfriend. All testified Cooper claimed to be a Naval lieutenant, boasted of having a master's degree in business administration and quickly asked them to marry him.
In closing arguments Tuesday, prosecutor Dorian Cotlar pointed at Cooper and said, "This defendant is a wolf in sheep's clothing. There's no better way to describe it. He is a predator. ... a wolf in a naval uniform."