(CNN) -- Lab results are back in the case of a teenager who died in a police shooting in St. Louis last week, and they show gun residue on the clothing and body of Vonderrit Myers, authorities said Tuesday. The residue was found on Myers' shirt, jeans and hand, according to a release from St. Louis police. "We're done as a police union standing in the shadows in these cases. We are actively defending the officer involved in the shooting," Jeff Roorda, business manger of the St. Louis Police Officers