I can see what When Evil Lurks is trying to achieve. Its an alternate take on reality, a horror infused, supernatural world, where demonic possession is an accepted occurrence.
Its done convincingly, with an everyday vibe, where a possession event is akin to a serious crime or perhaps, a natural disaster. The problem is, the treatment is deeply, violently disturbing, to the point where you start to ask if this is, in fact, adding value as a creative work?
Its a subjective point but I found this one too brutal and shocking, for me to really say I found it compelling. I think too, a more subtle approach could have been taken, with better results in terms of watch-ability.
In summary, makes the outlandishly otherworldly everyday, in a convincing manner but the delivery is on the heavy handed side of horror, to say the least.