George Zimmerman, acquitted in July in the fatal shooting of 17-year-old Trayvon Martin, was arrested Monday afternoon for allegedly pointing a shotgun at his girlfriend and pushing her out of her house as he packed to move out, the Seminole County Sheriff's Office said.

Zimmerman barricaded himself in the house Samantha Scheibe rented in Apopka, which he had shared with her since around August, Chief Deputy Dennis Lemma said at a news conference. She gave deputies a key, and they pushed aside furniture he had piled against the door. Zimmerman was unarmed and offered no resistance when he was arrested about 1 p.m. Lemma said investigators believe two weapons are in the home — a shotgun and an assault rifle — and are seeking a search warrant. The arrest report said Zimmerman had apparently locked up the shotgun before deputies arrived.

Zimmerman, 30, was booked for aggravated assault with a weapon, a felony, in addition to misdemeanor battery-domestic violence and criminal mischief. Scheibe was not injured.