SALEM – An Essex County grand jury reviewing criminal cases Wednesday handed up two narcotic indictments against a Dorchester man who allegedly was dealing cocaine and heroin in Lynn.Ernesto Serrano, 47, of 150 Ellington St., #1A, Dorchester, is charged with trafficking over 14 grams of cocaine and possession with the intent to distribute heroin.The charges stem from an incident in Lynn on of the afternoon of March 13 when he allegedly sold three twists of heroin to an undercover police officer near New Park Street.When police arrested him in his vehicle they reportedly confiscated over 14 grams of cocaine and additional heroin.Serrano faces a three year minimum mandatory prison term on the cocaine trafficking charge.Assistant District Attorney Marsha H. Slingerland is prosecuting the case for the commonwealth.The indictments handed up now move the case from Lynn District Court to Salem Superior Court where Serrano will be re-arraigned within a few weeks.Indictments are not an indication of guilt. Rather, a grand jury found sufficient evidence to warrant a jury trial in Superior Court, allowing for a more severe punishment.