The house is gated.. and they have a couple dogs...
When I think about it Aruba LE didn't drop the ball in MY eyes until they didn't hold the boys the first time.
When the Natalee's parents arrived she had not been missing even 24 hours... or right at it. We have absolutely no idea how many people miss their flights/boats. Even here in the states LE won't get involved for 24 hours for adults - on Aruba Natalee is an adult. I think once the parents arrived on the island and LE saw that the parents were freaking out and that this wasn't a "normal" missed the flight that's when they just started looking.
I heard N's mom say on tv that they were at Joran's gate 12 hours after she disappeared.