Absolutely! Which is why I'm pretty forgiving for these kinds of movies. However to me there's a difference in suspending disbelief in something unnatural/supernatural (be it aliens, voodoo, or a super killer) vs things like police behavior or using tech. It also depends on the reality that is put forth in the movie. If you are largely showing the police as competent, yet stumped, you can't have one of the big reveals be that they completely overlooked obvious clues. If they were being shown as bumbling idiots, then that's a different story.