>> reporter: the hoody was also tested by a firearms expert who said zimmerman's gun was actually touching the fabric when he fired the fatal shot. >> what did you find distance wise when you conducted the test with this particular sweatshirt? >> this as well was consistent with residues of a contact shot. >> so again, evidencing that the end of the gun was against the material when it was fired? >> yes. >> reporter: the prosecution also pointed out the night he killed marten, zimmerman carried a fully loaded weapon with an additional round chambered and ready to fire. but on cross-examination, the defense got the witness to admit that was not out of the ordinary. >> you do not consider that to be an unusual occurrence? >> no. >> reporter: earlier, the state was out to show that zimmerman did not just want to be a cop, he was trying to learn how to become one, studying criminal justice at a local college. on the stand, a former professor