I would think that there are plenty of ways a clerk at a bank could set off an alarm that would notify the police and take air samples around a thief. One could put a piece of cardboard under the hundred dollar bills. If under duress one could just remove the cardboard with the bills. Or maybe the bank would take air samples from everyone just in case of a problem. There are probably ways of defeating this. If one were to wear a air and water tight garment and take a shower in it soon before attempting the robbery but this would significantly increase preparations for the robbery.