Part The Silence of the Lambs, part Encyclopedia Brown: High concept doesn’t get more plastered than Slaughter of the Innocents. (Of course, Encyclopedia Brown never tackled a case in which the source of a stray pubic hair was at issue.) An FBI sleuth (Scott Glenn) gets help from his precocious, computer-crazy son (Jesse Cameron Glickenhaus) in tracking down a religious wacko who kills kids. The weird thing is that the movie almost works — the father-son relationship is remarkably uncloying, and the nuts and bolts of their unlikely collaboration are convincingly conveyed. But writer-director/costar’s papa James Glickenhaus violates the cardinal rule of mystery storytelling by making the investigators far more clever than the crime’s actual level of difficulty demands, especially considering what a sloppy nutcase the killer is.