Adult son autopsy came back manner of death undetermined. There was foul play. Do I need an attorney?

Death undetermined. Toxicology report showed high levels of wifes medication. Wife and wifes friend said he hung himself. No evidence of hanging and the stories keep changing as to how they found him. We are certain she drugged him and staged the hanging. I need medical records from the 2 hospitals before his death. Wife just won a million dollar medical practice settlement. My son was trying to leave her & she did not want to have to share the money. Took place in Bucyrus, OH small town police have low budget. Do I need an attorney to get this investigated fully, if so what type of attorney do I hire.