And that's a problem. Because trained drug dogs are trivially (even unconsciously) manipulated into falsifying probable cause using cues, where they are even trained in genuine detection in the first place. A complete lack of negative controls in "training" is apparently not uncommon - in which case they're not even really trying to hold up the pretense that accurate detection is the goal.

https://www.animallaw.info/article/cueing-and-probable-cause...