Cops have identified one of the five people arrested in the mistaken-identity slaying of 15-year-old Lesandro “Junior” Guzman-Feliz. Kevin J. Alvarez, 19, of the Bronx, was named Sunday night as one of the alleged killers. He was charged with second-degree murder, manslaughter, gang assault, and assault, according to police. Authorities would not say which person...