dr. fierro. it's my understanding the author actually worked with dr. cable rÉsume. >> absolutely. >> reporter: dr. fierro came to court with her report, and it was a bombshell. art gonzales had always maintained that he had shot julie four times while she stood facing him in the kitchen, coming at him with that knife. examining the photos from the scene and the autopsy photos of julie, dr. fierro noticed something. in csi language it's called a shored bullet. >> a shored bullet is a bullet that as it exit is met by resistance by something firm and hard. >> reporter: dr. fierro says she clearly saw a wound on julie's back caused by a shored bullet. >> and in this case, the bullet couldn't even go any further, so it had to be a hard surface. >> reporter: given the possibilities at the crime scene, to her that could mean only one thing. >> she was down when she got that shot. >> she came to the remarkable conclusion, and the inescapable conclusion, that julie gonzales was shot on the floor. >> she was not standing up. >> reporter: the prosecutors saw a gam