Ben Wallace’s mug shot. (AP)

Wallace, 37, was arrested at about 3 a.m. Saturday in Bloomfield Township, Mich., when officers spotted his Cadillac Escalade traveling erratically, authorities said. An unloaded pistol was found in a backpack and Wallace’s blood-alcohol level was over Michigan’s 0.08 limit.

He was released on a $5,000 personal bond and is scheduled for a court hearing Monday.

He faces a five-year felony charge on the weapon charge, the Detroit Free Press reported.

Wallace told police that the gun is registered in his wife’s name and that he does not have a permit to carry it. He said he threw the .28-caliber FNH and a full magazine of bullets into a backpack because, according to accounts of the police report, “he wanted protection as he drove” from his home in Virginia to Detroit on Friday. According to the Detroit News, Wallace said he “completely forgot the gun was in his backpack and when he got back to Michigan went out with his buddy and had some drinks … .” The police report by Lt. Mark Paquin notes that Wallace said that “if he had known tonight was going to end up this way, he would have done things differently.”

“Mr. Wallace said he knew he was in the wrong, and he shouldn't have had the gun, he also told me that he was a criminal justice major in college,” Paquin wrote in the report.

Bloomfield Township Captain Scott McCanham described Wallace as “totally cooperative ... Nothing but a gentleman the entire night.”