The family of the American teenager shot dead by a police officer wants a "Michael Brown law" introduced, CNN reports.

They've just called for police to have mandatory cameras, saying they don't need the game of conflicting testimonies.

Brown family lawyer Benjamin Crump says the grand jury system is unfair, and a first year law student could have done better at questioning Darren Wilson, the officer who shot the 18-year-old.

"This process is a broken. The process should be indicted."