"K-9 Onboard" joke

A man is sitting on a plane which is about to take off when another man, accompanied by a dog, board it and occupy the seats alongside him.
Noticing the first man looking quizzically at the dog, the dog handler tells him they work for the airline and says, "Don't mind Rocky, he's a sniffer dog. The best there is. Once we get airborne, I'll set him to work and show you what I mean."
The plane takes off and levels out when the handler says, "Ok, watch this. Rocky, Search!"
The dog immediately jumps down from his seat, walks up the aisle and sits down beside a woman for a few seconds. He then returns to his seat and puts one paw on the handler's arm.
"Good boy," the handler says. He then turns to the first man and says, "That woman is in possession of marijuana, so I'm making a note of this, and her seat number, for the police who will apprehend her upon arrival."
"Wow, that's unbelievable," exclaims the first man.
Once again the handler sends the dog to search the aisle. The dog sniffs around, sits down beside a man for a few seconds, returns to his seat and places both paws on the handler's arm.
The handler tells him Good boy, turns to the first man and says, "That man is carrying cocaine, so again I am making a note of this and the seat number."
"This is incredible. I've never seen anything like it!" the first man says.
Again the handler sends the dog to search the aisle. Rocky goes up and down the aisle of the plane. After a few minutes he sits down next to a passenger then comes racing back, jumps up onto his seat and shits all over the place.
The first man is surprised and disgusted by this and asks the handler, "What the hell is going on now?"
"He just found a bomb!" the handler replies.