Perhaps this is a simple case of someone that got too deep into child *advertiser censored*, acted on impulse and the fantasies he had built up in his mind with this unfortunate victim, then got spooked when she fought back and he ran straight for home. Everything that happened after he kidnapped the victim from the library appears random, reactive, and not well organized. It's as if her knee in his face woke him up from his fantasy and he tried his best to run back to his normal life. Sometimes the simplest answer is the right answer.
There are aspects of this developing story and case that lead me to consider other scenarios with much more significant and wider ranging potential impacts, but I stay open to the simpler answer if the facts in the case lead that direction and stop there.