What's an autopsy going to show? That she has broken bones?
What would broken bones show?
That she was laying in bed for 15 years?
It wouldn't prove that Michael hurt her. People who are in bed for a long time get bones that are so weak they can't sustain their own weight.
So even changing Terri's sheets can cause a bone to snap.
What's an autopsy going to show?
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I'm not sure because I'm not a doctor, but what if it did show something. With all the forensics they have available...well, it's worth a shot.