There are four criminals namely Rough Robbie (has row in the bus all to himself), Tough Tony (sitting right by the air conditioning vent), Bold Bob (squeezed and next to the bathroom), and Gunshot George (sleepy).
The answer is:
Boldly Bodacious Bobby or Bold Bob is most likely to cause the guard problems and behave aggressively. This is because he is squeezed next to the luggage and is also next to the smelly bathroom.