Holy shit, I just found his story Angels Scream. It's 12 chapters (you can find it on ASSTR). It's about this pedo who kidnaps his 5 year old niece, tortures her, and kills her.

It's actually a lot more complex than that with a fascinating love-hate relationship between the two, and a very good insight into the mind of a scared child. It's nothing at all like the typical snuff stories where it's just "cock does this girl screams cock does that girl screams louder".