I don't think drugs were involved, although i do think mental illness was present in both Michelle and Joe, it in no way clouded their actions on the night of the murders. I don't think they were on drugs that night either. Their heads had to be clear enough to hide the parents bodies, and then lay in wait for Michelle's brother and family to arrive. There heads were clear and they knew exactly what they were doing, they knew it was wrong, and they didn't care. It is obvious as someone else stated, that Michelle's family loved her. For some reason in her twisted mind she either made herself doubt this, most likely as they were asking her to pay rent. Although the blacked out windows sounds like drug related behavior, i believe this twisted couple made themselves paranoid plotting these murders for awhile and that's why they blacked out the windows. If they had purchased the guns legally the past summer or awhile ago, they were fostering this fantasy of murder for awhile in their heads, probably to the point of obsession. This in itself, would make them paranoid that someone would find out their plans. There's no way an insanity plea would work for them as it was all premeditated and they obviously knew well enough to hide the parents bodies so they wouldn't look suspicious when the others arrived.
As for jailhouse vengeance, those that kill children are on the lowest of the totem pole along with the perverts and rapists. I'd guess Joe would have a harder time than Michelle, although she will get her share, especially when they first arrive at their respective prisons to serve their sentences.
I also find it a bit odd that there isn't more an internet history on these two. No Myspace???
