"You better stop runnin your mouth or the other officer will find a reason to lock you up tonight."
There is no threat there, only speculation (and possibly a warning to snot nosed punk to quit being an ass so you can proceed through the checkpoint.)
Now there's a bunch of bravo sierra.
A man with a deadly weapon and the power to incarcerate you and make your life infinitely miserable says to you "You better stop runnin your mouth or the other officer will find a reason to lock you up tonight," and you claim that doesn't constitute a threat?
C'mon.