CEDAR RAPIDS — Officer-involved shootings should be looked into by independent investigators and handled by special prosecutors if referred to a grand jury, the social activism group Iowa Justice Alliance announced Saturday in making a dozen demands in the wake of a traffic-stop shooting three months ago. Organizers unveiled the list during a “Standing in Solidarity” demonstration inspired by the case of Jerime Mitchell, a black motorist who was shot and paralyzed by white Cedar Rapids Office Lucas Jones during a Nov.