I think drugs/alcohol may have played a part in dulling the senses which led to the failure of basic security precautions. However, that is neither criminal or negligence (in the legal sense). There is a basic right to security in one's own home/property. Children have an even greater right to presumptive security, especially while asleep in their beds. That predators take advantage of opportunity created by human failings, does not make their criminal acts less criminal, or shift the responsibility to the victims. It makes them more heinous and morally corrupt. To prey upon the weak is a great moral wrong.
The problem is predators, the solution is predator control.