the culprit (spoilers)
There seems to be a consensus on this board that Dror was guilty of the murders. I'd like to explain why I drew a different conclusion, and would be happy to if someone wishes to engage my points.
The closing scene shows Rami at Dror's house, telling the police chief on the phone that he hadn't found anything. In the adjacent room, there is the prone body of a young girl. I didn't get a good look at her face; I assumed it was Dror's daughter, but it wouldn't substantially affect my argument if it were Micki's. Micki does say he considers Rami of finding anything when the case is assigned to Rami but this body is in plain sight in a house Rami says he has searched. So, it looks to me like Rami is concealing this crime that is on display in Dror's house. Does this mean he did it? Not necessarily, but that struck me as the most obvious explanation.
Could this be Dror's crime that Rami is keeping to himself for whatever reason? This seems to me possible but unlikely. Dror is already aware that Micki is shadowing him (after finding him parked outside Dror's house); he'd have to be very foolhardy to attack anyone while under surveillance, let alone Micki's daughter. And even if he were that daring, he's NOT aware that Gidi is shadowing him and it seems unlikely that Gidi would just sit back and snap photos while Dror dispatched one more child. It's not impossible that Dror would slip out unnoticed by both Micki and Gidi, kidnap Micki's daughter, bring her back to his house without anyone seeing them, kill her and then go out to walk his dog just when his two tails finally show up but it seems so unlikely; he'd have to be very reckless to attempt it and everything would have to go his way for him to pull it off. Notice that bringing his victims home doesn't seem to be part of the killer's M.O.; Gidi's daughter is killed and abandoned in a secluded, out of the way spot.
Speaking of Gidi, he does offer Dror a quick death by bullet if he discloses the location of Gidi's daughter's head. The grizzly method he chooses would certainly break his word. I'm not saying that's beneath Gidi (nothing seems to have been beneath him), but it seems to me more likely an expression of his ire that Dror is, as he sees it, holding out on him. Of course, Dror *might* hold out on him even if he were the killer, but it doesn't seem like he has much of an incentive to do so. As he tells Micki, it seems reasonable to expect that Gidi will come back and butcher him if he doesn't find the head in the location Dror specifies. It seems to me much easier for Rami, who is unsuspected and off camera for most of the film, to have committed the crime and/or tried to incriminate Dror.