If two people were killed in a fire on Thursday, would the autopsies already be done by Sunday? I imagine there's a time limitation based on decay.

What happens to the bodies after the autopsies?

I need for the bodies to be able to be examined on Sunday due to new information. Is that possible or does my timeline get in the way? It's not the end of the world for my story if it's not possible but it does complicate matters.

Also, side question:
If detectives from property crimes originally got the arson case, but then the bodies were found, would the case get transfered automatically to homicide? What might influence that?