The Clerk of the Court in the county where he is or was held. You can request all of the documents pertaining to his case. There might be a small charge to copy your request, but it will be the most accurate information avaiable to you.
https://www.inmateaid.com/ask-the-inmate/how-can-i-find-out-why-he-is-in-prison#answer
Accepted Answer Date Created: June 24,2016