
Shortly after 10 pm, Myers pulled the gun which accidentally discharged in the face of his friend. Presumably there were witnesses or some other way that the police ruled out an intentional act that would warrant a higher charge.
Manslaughter fits the alleged crime, if proven. It would not seem to leave much for a defense absent a denial of being the shooter. This is the type of case that is generally pleaded out with a request for leniency.
Source: CNN
