dan nash asked for that test to be done. >> by now, dwight was looking carefully at dan nash. he made it clear that he had a lot of problems with nash's reputation for truth and honesty under oath. from there, we started interviewing former prosecutors and the number of former court personnel who expressed concerns about his reputation for truth and ferocity. >> remember how nash was presented as a blood spatter expert? he was not. in fact, he had not even taken of bloodstain analysis class when he investigated the death. he took a course the following year but not an expert when he testified at trial. dwight set out the best in the field. >> i found two of the world's most renowned blood spatter experts. >> he sent the photos to both of them. >> they both independently came to the same conclusion. >> that dan nash was dead wrong. one of them row, the bloodstained evidence in the presence of gunshot residue on the right hand of lisa jennings are consistent with his self- inflicted gunshot wound. is any lawyer will tell you, undoing a jury's guilty verdict is almost impossible.