Medical Examiner: McNair's Girlfriend Fired Gun

We just spoke with Tennessee assistant medical examiner Dr. Feng Li, who tells us preliminary test results in the Steve McNair death show Sahel Kazemi fired the gun that killed both of them.

Feng -- who conducted autopsies on the two bodies -- told us he was able to make the determination from the crime scene investigation, police interviews, autopsy findings and preliminary lab results -- which include a gunshot residue test.