Gang members Jose Medina, George Marron, and Raymond Vallejo (defendants) instigated a fistfight with Ernie Barba in retaliation for Barba's perceived failure to show them sufficient respect. Although Barba belonged to another gang, the gangs were not engaged in any active rivalry. Immediately after the fistfight ended, Barba started to drive away in his car. Medina took a gun and shot Barba to death. The State of California (plaintiff) prosecuted Medina, Marron, and Vallejo for murder. At trial, expert witnesses emphasized the importance that gang members place on maintaining their reputations and retaliating for disrespect, the potential that a gang dispute will quickly escalate into violence, and the prevalence of guns in violent confrontations between gang members. The jury found Medina guilty of the fatal shooting, and Marron and Vallejo guilty as Medina's aiders and abettors. An appellate court reversed Marron's and Vallejo's convictions, and the state appealed to the California Supreme Court.