Sure, but that's different than not telling the local police department. Because they will show up with K9s and guns. And then it becomes a very dangerous situation.

That sounds like a problem with police procedures and accountability. It's weird to blame potential victims for that.

And in this case, notifying the police would have seemingly affected the test. Based on the reaction they did have, I would guess such notification would have resulted in the police doing many more drive-bys of the courthouse and generally being alert.