To be fair, the title can be commonly taken to mean that either (1) the killer goes after lolicons or (2) that the killer is a lolicon (i.e., killer of... vs. killer is...); what it establishes at the minimum is that the killer is somehow associated with lolicons in some manner. Compare with Zodiac Killer (he did not kill zodiac signs, nor was he a member of the zodiac himself, only that he used the name), or other such noun adjuncts: does face mask refer to (1) a mask for a face (a somewhat redundant concept, when one thinks about it), or does it refer to (2) a mask that looks like a face (which is not as redundant as the first, ymmv)? English has its own quirks, just as Japanese (and every other language on earth) does; trying to fully understand SZS or Bakemonogatari without a little explanation of the puns/expressions used can be quite the bewildering experience. These quirks can be used to good effect in the story itself: just imagine the little heroine of this story going up against against someone who actually raped and killed children.