Las Vegas police are investigating an allegation of battery against R&B singer Chris Brown. Authorities received a call shortly before 10:30 am Saturday about the alleged battery at the Palms Casino Resort. A police statement Saturday evening said an altercation took place in a room at the resort when the woman went to take a picture of Brown. The woman said she was struck by Brown and that he had taken her cellphone. Detectives tried to speak with Brown at his hotel room, but the singer left before police had arrived.