dr. bulicsee where the shell casings may land when the gun is upside-down, and see whether an upside-down gun, once fired, could have caused the injury above michelle's eye. sheriff shoar has been critical of the outdoor crime scene reconstruction by the fdle. so today we are going inside. we've created a replica of the scene based on scene photos. we use a mannequin for the purposes of this test. and you can see this is the layout of the bedroom, door right here, people came in and out of the room this way. we ask professor peter diaczuk, a forensic scientist at penn state, to conduct a firing test for us. back in 2013 diaczuk reviewed the case for a "frontline"/"new york times" investigation. professor, how well do you know the gun that was used in this case? >> i am familiar with the, with the firearm. >> reporter: have you fired that gun before? >> many, many times. >> reporter: in those initial set of photographs taken at the scene, there's no visible sign of any shell casings around miche