If I recall correctly L&L weren't pedophiles and the victim wasn't sexually abused.Pls correct me if I'm wrong,don't remember much about this case.
http://www.trutv.com/library/crime/notorious_murders/famous/loeb/3c.html
"Essentially, the whole murder/kidnap scheme was an elaborate game to entertain and intellectually challenge two bored students. They immensely enjoyed developing and refining what they were certain was the "perfect crime," befitting their superior intellects. Collecting the ransom without being caught was a more difficult problem for them than the kidnapping and murder. They had put together several different plans for the ransom collection, researching each plan diligently.
"Richard knew Bobby. He was a neighbor and had played on the Loeb mansion's tennis courts. Richard asked him to look at a particular tennis racket and Bobby agreed. As soon as he was in the car, Bobby was hit on the head with a chisel and a cloth forced down his throat, which led to his suffocation.
""The diabolical spirit evinced in the planned kidnapping and murder; the wealth and prominence of the families whose sons are involved; the high mental attainments of the youths, *the suggestions of perversion;* the strange quirks indicated in the confession that the child was slain for a ransom, for experience, for the satisfaction of a desire for "deep plotting," combined to set the case in a class by itself."
"adding weight to the "perversion" testimony, and causing from then on, a notion in the mind of the public that the entire kidnaping was an act of perversion, that Robery Franks was sexually abused, an idea that remained with the case, that Leopold wrote about in his autobiography, citing a time when he was denied a transfer to the honor farm, because "sexual criminals" were not allowed there. "" - end of quotations
--- the alleged sexual abuse of BF was an issue raised in trial, and by psychiatrists who examined them. The claim does exist in transcripts.
I have speculated if the IDI was motivated by L&L to commit "the perfect crime" as an "intellectual" challenge. I know that the RDI's here will dismiss such a theory out of hand.