Laughter came from the audience during a presentation Monday when attorneys Laura Hepokoski Nirider and Steven A. Drizin played video footage of a Calumet County, Wis., sheriff’s investigator asking then 16-year-old Brendan Dassey: “Who shot her in the head?”The laughter wasn’t a reflection on the serious and tragic subject of the question, the 2005 murder of Teresa Halbach. Rather, the audience — a room full of experienced attorneys — seemed amazed at the leading nature of the question …