A massive march planned to protest the death of a man in police custody is now being billed as a "victory rally" after Baltimore's top prosecutor filed criminal charges against the six officers involved in the man's arrest.

Thousands of marchers who are expected to hit the streets this weekend will now do so to celebrate the decision by State's Attorney Marilyn Mosby to charge the officers with felonies ranging from assault to murder.

Freddie Gray's death from spinal injuries a week after his April 12 arrest became a rallying cry against brutality and social inequality in the city.