(October 11, 2018, 1:23 PM EDT) -- MILWAUKEE — A federal magistrate judge in Wisconsin on Oct. 3 ruled that an engineer could provide expert testimony on ballistics and the shape of an indentation on the rear driver’s side door of an informant’s car because he was qualified to proffer his opinions but that he was unqualified to discuss trace elements that would have been left behind on the door, as well as the credibility of the defendant (United States v. Derrick L. Harris, et al., No. 17-CR-167, E.D. Wis., 2018 U.S. Dist. LEXIS 170537)....