It is not the law that is so different - it is the inept approach by the police and detectives, et al involved. They seem to be busier protecting themselves, friends, prominent people, etc. and worrying about their country's "image." All the while the whereabouts or condition of Natalee seems to have slipped to secondary importance.
Also, I wonder, if they think there is a possibility that this will lead to a big crack in some criminal ring so they have focused on the larger opportunity, rather than just on locating Natalee. Her parents must be going crazy. It just seems to be taking way too long. Something else must be going on inside that police station.
What I fear is that the drug/trafficking ring involves some of the 'higher-ups' in the Aruban government. If that's the case, this will never be solved. And even worse, if NH is still alive, they'll quietly "get rid of the evidence" because she knows too much and they can't just let her go now.