Brown: "How could I be that person?"

Chris Brown has said that he never had problems with anger before he assaulted Rihanna.

Speaking on 20/20, the singer apologised for his behaviour and added that he doesn't know how he could have done it.

"I never, ever had problems with anger," he said. "No domestic violence with any of my past girlfriends or any altercations. I was never that kind of person... It's like, how could I be that person?"

He added that he was unhappy with his online apology and said that he had been trained by PR advisors before making it.

"My head wasn't really giving me a chance to be me," he explained. "It was genuinely from me, but it wasn't projected genuinely."

Brown said that Rihanna's negative remarks about him are "difficult" and "hurt", but continued: "It's just something that I have to be responsible for."

He also confirmed that he isn't in touch with his former girlfriend, explaining: "I've said, like, everything I can with me and her. Me and her have talked. Me and her have spoken about the situation. And she knows how sorry I am."

> Chris Brown tells '20/20': 'I was wrong'