Regarding the raincoat/tarp "mystery":
1) We have Shelley, the trusted caregiver, stating that Alex showed up at Almeda at 6:30 IN THE MORNING soon after the murders, holding some sort of wadded up blue vinyl.
2) Alex DENIES this EVER HAPPENED. and that's it?
C'mon now, why on EARTH would Shelley lie? Seriously. How could she get that wrong? Alex isn't saying "Oh, it was later than that", he is saying it NEVER HAPPENED. If it NEVER HAPPENED, then that means that either Shelley has decided to completely fabricate a story that will not only put her in hot water with her employers, but also puts her at risk of criminal charges for lying to law enforcement, OR, Shelley has just hallucinated the entire event.
Who benefits from Shelley's lie/hallucination? No one.
If, on the other hand, its true, and Alex is the one lying, if his denial is a lie, we have to ask ourselves the very same question: Who benefits from Alex's lie? If he was there that morning, at 6:30, with a wadded up blue raincoat, why is he lying about it? Guys, this is just ONE of MANY instances in this case where the jury is being asked to suspend disbelief and to ignore common sense.