Jon Jones allegedly pulled his fiancée's hair and then headbutted a police car, leaving a dent in the hood and chipping paint, during his Las Vegas arrest early Friday morning, TMZ Sports has learned.
According to a Vegas Metro PD arrest report, cops were called to Caesars Palace around 5:08 AM for a "domestic disturbance" in a hotel room ... involving a white female who was "bleeding from her nose/mouth" and a "black male adult who is a professional MMA fighter."
When police arrived, they spotted Jon walking near the hotel, where they stopped and detained him.