As I recall the police interviewed scads of kids from the area and there were lots and lots of rumors going around with these boys doing some bragging about their part in the crime. I don't think the stepfather did anything. This area strikes me as a low income area. A lot of dysfunction in the both the victims' and the perps' homes.
It seems to me I read the mother's autopsy somewhere and she had been in a deep,deep depression following the death of her child, was mixing alcohol and drugs, and just didn't wake up one day. I think it was an accidental death. The stepfather is just an easy patsy because he isn't a clean cut joe, but, hey, I have known some rowdy bikers in my time (no..I am not a biker chick) who were better parents than some of the suits I worked with. So just because he might seem like a lowlife (if that is your perception of him) doesn't mean he cut up these boys and mutilated them like that.
This case was not about child abuse. At least not abuse by a parent figure. It was about some very troubled kids who fell into an evil abyss (their version devil worship) and did the unthinkable. It is similar to the case back east where the little red headed kid killed his 4 year old neighbor one day in the park. And seems like there was another where the little kid knocked on the door and the teenager home alone killed him.
Seems like all of theses cases occurred around the same time. Back then we were filling our kids heads full of dark, gory horror films...Freddy Krueger, Chainsaw Massacre, Jason (Jamie Curtis' ride to fame). Dungeons and Dragons was a big thing and another game called Magic. And in the south there was lots of interest in satanism. Even where I live, which is not that far from West Memphis (a couple of hundred miles, I think), and we had trouble with kids going out into the woods and drawing pentagrams and sacrificing small animals. One house I lived in I found evidence of strange rituals in the attic. Couldn't wait to move out of that one. Point is, this is a haunting case because of the nature of the crime and who did it, but I really believe the right people were convicted.