Getting autopsy results

Several years ago my Uncle died under suspicious circumstances. I am trying to find out the cause of death and I have been trying to get a copy of the autopsy or death certificate. His two children will not communicate with any of the family members so that is a dead end. I know that in Texas an autopsy can be public record or private depending on who ordered it.
I have sent off for a copy of the death certificate. Does anyone know of a website where I can make a request for public autopsy results?