Ok see an unsolved mystery is one thing, because then you could argue that maybe the next of kin are trying to invite fresh perspectives onto the case, but a lot of the times it’s just making ghoulish entertainment out of a case we know the answers to.
The toolbox killers are the biggest example of it, it’s cut and dry that they did what they did, and even worse that having to endure interacting with the evidence is a risk factor in inducing PTSD and suicidal tendencies, and yet like an idiot the news crew still showed up just in time for the court gallery to all flee the courtroom and leave the door open for long enough for what I can only call the single most tortured scream I’ve ever known a human to make to get blasted onto the airwaves, and the psychopaths just keep recording the door!