You wouldn't believe what it takes to actually prosecute these scum. And apparently Arkansas isn't the only state like that. Basically, without a confession or DNA evidence, they walk.
Any good DA can and will prosecute the scum... some just choose not to do so. No, they may not win the case, but they can charge them with a crime and bring them before a jury.
Scott Peterson was found guilty on circumstantial evidence...because a DA charged him with a crime.
those poor kids .. sounds like they are doomed to a life of hell