The bandits' rented getaway car, found near a tennis court, a fire extinguisher was left off inside to destroy evidence.
This is a very sad event, and security should be improved. But really, security should have been improved long ago. It should have been restructured ten years ago in the aftermath of the first Munch theft (different Scream different museum, same city). All the ADT systems in the world won't bring back those two paintings.