I can't for the life of me envision a scenario where these two - CD and LCYLRVD - discover or otherwise stumble upon a toxin or drug that can't be discovered by a modern forensic autopsy. You don't just Walter White your way into a poison bean. I think AC died as natural a death a man in his early 50s could die. The life-style, the diet, and the stress of having realized that you were pawned into committing 4 maybe 5 murders all conspired to put him down. Surely it had some effect on Chad and Lori, tho.
Thinking about when this first started to come to light, Chad was LARPing his own Mormon fan-fiction predicting the Apocalypse, and Covid hits soon after. Some of those early images coming out of Europe sure had that End-of-Days tinge to them. The BLM riots and Jan 6 shenanigans; the Tweedles probably thought they were right on course with their... 'visions.' At some point the two probably thought they had to get Alex gone, and he up and taps out on his own? If they weren't already 100 percent invested, that had to staple them permanently to their delusions.
I'm sure they both still believe their story, that these literal trials and tribulations will end and they'll have the last maniacal laugh. Every morning Lori wakes up, thinking this is the day the trumpets blast and the prison walls crash and El Chaddo can get back to storming her beaches.
It makes you wonder, how far gone are Melanie, Melanie, David, Zulema and whomever else is part of this harem of the absurd? Anybody get any deprogramming of which we are aware? If by some freak Chad gets found innocent, it won't take much of a shove, IMO, to get part or all of this group back on board. From the testimony we've heard, none strike me as being blessed with any critical thinking.