The counterpoint to what you say is that the evidence comes from personal documents/conversations/etc. they obtained, and if they released some of that but not

The counterpoint to what you say is that the evidence comes from personal documents/conversations/etc. they obtained, and if they released some of that but not all -- in order to avoid publicly releasing any murder-for-hire bits -- you would be here saying that the selective release is suspicious and that they should release everything in order to avoid damaging his reputation through cherry-picking evidence.