A video posted to Facebook appears to show the moment a homeless man is shot dead by Los Angeles police officers . In the video a group of officers can be seen scuffling with two people. One man is held on the floor and repeatedly punched, while apparently being shocked with a stun gun. 'Drop the gun' can be heard being shouted, before 5 or six shots ring out. The camera's view is obscured by another police officer who is restraining another person involved in the altercation.