SACRAMENTO, Calif. — Sacramento police say that two groups of men began firing at each other in Sunday’s shooting downtown and that at least five shooters were involved in what authorities are now saying was a gang dispute that left six people dead and 12 wounded. “Evidence in the case indicates that at least five shooters fired guns during the shooting, and that an exchange of gunfire took place between at least two groups of men,” police said in an announcement Wednesday. “As detectives continue to identify shooters and weapons involved, the number of identified shooters may grow beyond five...