There is no mention of his involvement in the killing.
While Baker was not involved in the murder of his daughter, he is guilty of some much more minor, but still relatively serious crimes involving fraud, identity theft, and assault that came to light during the murder investigation. It was decided not to imprison him on compassionate grounds, and also to drop some remaining outstanding minor charges - he is seen as a victim of crime as well, having lost his daughter - but to instead immediately deport him to Australia. He planned to come back here anyway to bury his daughter, the deportation simply means he won’t be allowed back into the US at a future date.