Reading through these comments it seems that many lemmings have wildly optimistic ideals about ethics in the "true crime" genre of documentaries.
Even for sincere documentarians, presenting unvarnished history accurately and completely is an impossibility. For the bad-faith actors, you'd be amazed at how much is outright staged or otherwise faked. The only rule is that it be entertaining.
As far as "true crime", the question of "should we even make this" is pretty ethically fraught. True crime is cheap, popular, and stuffed to the brim with hacks and bad faith actors.