Protesters march on police HQ over filmed beating

Hundreds of protestors marched on a Los Angeles police headquarters last night demanding the arrest of a white officer who was filmed punching a handcuffed black teenager.

Black community leaders were joined by national activists, including the son of Martin Luther King Jr, as outrage swelled over the latest accusation of police brutality in a city tarred by the 1991 Rodney King case and the bloody riots the following year.

"No justice, no peace, no racist police," chanted protesters carrying banners such as "This happens every day in LA".

A cameraman who videotaped officer Jeremy Morse slamming the handcuffed 16-year-old, Donovan Jackson, against a patrol car and punching him in the face was himself arrested on Thursday evening.

Officers arrested Mitchell Crooks, 27, outside the Hollywood studios of CNN on outstanding warrants for petty theft, driving under the influence and a hit-and-run.

He let out several screams as he was caught, yelling, "Help me, help me". The arrest was captured by security cameras at CNN, where he was due to be interviewed.

A lawyer for Mr Morse, who has been placed on administrative leave while the incident is investigated, said his client's use of force was restrained and that Mr Jackson had grabbed the officer's crotch.

"We will put that video tape in context ... You cannot see what the subject is doing with his hands just prior to being hit in the face, said John Barnett.