The Opa-Locka Police Department in Florida on Wednesday argued before an arbitrator that one of their own officers deserved to be fired -- for the sixth time -- because he left his department AR-15 assault-style rifle with a friend.

The department told arbitrator Jeanne Wood that Sgt. German Bosque should be terminated because he had left a city-owned, 30-round assault rifle like the one used to slaughter 20 elementary school children last year in Connecticut in the hands of his then-girlfriend's father.

Bosque’s attorney, however, argued that the rifle was in good hands with the girlfriend's father, who Bosque called "Daddy," because he was a licensed security guard.

"Anyone can legally purchase this weapon," union attorney Andrew Axelrad said on Bosque's behalf.

"Not just anyone can purchase one from the Opa-locka police department," city attorney Joe Geller shot back.

According to WFOR, Bosque has been fired eight times by three police departments in Florida, including six firings from his job at Opa-locka. WFOR noted that Bosque was the "most disciplined, fined, fired, arrested police officer in the state."

Over the years, he has faced allegations of busting the skull of a suspect, beating juveniles, having drugs in a patrol car, stealing from suspects, falsifying reports, conducting an unauthorized car chased where four people were killed and "calling in sick…from Cancun."

Arbitrator Jeanne Wood was expected to make a decision about Bosque's job within 60 to 90 days.

Watch this video from WFOR, broadcast May, 2, 2013.