There's a reason why he got the lightest sex offender conviction in US history. Very likely he was providing information on his associate's exploits as part of a deal. Once they knew he was squealing it was only a matter of time before they fixed their problem.
I thought we have a lack of any evidence. No witnesses, no footage.
Really, Wikipedia's article on it sounds like no one is that sure.
It's the title of a chapter toward the end of Brown's book. A criticism, because she never answers the question or gives any evidence.
But not beyond a reasonable doubt?
I look at it like this: a murder is plausible because there were definitely some powerful people who wanted him dead. But for a murder or a hit to have happened there'd need to be a whole slew of extremely difficult tasks to set it up and leave zero trace. Also, it's thoroughly plausible that he killed himself and it would have been really easy to do it without any complicated plot. Occam's Razor says suicide.
I'm entirely prepared to accept that someone in his position would attempt suicide, but from everything I've read, it seems implausible that he coincidentally happened to choose a time to do so, precisely when it would leave no evidence. If he did kill himself, it only seems plausible that he did so when he did because he was told that he would be able to go through with it.
I don't think that's a coincidence. He knew his suicide watch was expired. The story about broken cameras was exaggerated because no cameras were ever pointed at his cell. Only one camera of many malfunctioned. There was ample evidence showing no one approached his cell. I'm also assuming the sleeping guards happens all the time at every jail and just never makes national news.