The grand jury for the Sean Bell shooting is hearing from witnesses this week and next. Yesterday, three friends who saw when Bell, was fired upon by police last November, testified, saying that the car Bell was driving was moving slowly.

The undercover police officers who fired on the unarmed Bell and his friends maintained that Bell was driving quickly and had hit one of the officers, therefore allowing the officers to claim self-defense. The witnesses, who included Jean Nelson, the so-called "fourth man," also said the police never identified themselves.

The two men who were in the car with Bell, Trent Benefield and Joseph Guzman, are testifying tomorrow. Three of the police officers involved are testifying next week. Then the grand jury, which has been convened since January, will determine whether there's enough evidence for the case to indict the officers.

This chart from the Manhattan DA's office is helpful to show how criminal justice process works. The Sean Bell shooting is being handled by the Queens DA Richard Brown.

Photograph from a Sean Bell shooting protest last December by kerfuffle & zeitgeist on Flickr