Precisely, and in my experience of many years as a trauma/ER nurse we were taught the very strict rules of not disturbing evidence, when the patient was a victim of violence or died as a result of an MVA. If we had to remove certain clothing for instance to treat a patient with a gunshot wound, we had to be careful not to cut through the evidence on the clothing. We had to retain the deceased patient carefully, not allowing anyone in the room except supervised know family members, until the authorities could collect crucial evidence. They then notified the coroner so we could release the body for further forensic examination. I never ever witnessed an ER doctor or surgeon sign a death certificate. The doctors were interviewed by the authorities as to the cause of death, but in my experience they never signed a death certificate.