I was sitting in the coffee shop facing away from the front counter when I noticed the reflection of a man wearing a bright yellow vest and a baseball cap walk up to order a coffee. It's important for this story that I was looking the other way and only saw the reflection of a man and a few items and didn't turn to look behind me until the very end.
What person wears a baseball cap and a bright yellow vest as part of their uniform? Often construction workers will wear a bright yellow or orange vest to make themselves easily observable on busy roads. But in my experience, the only person who typically wears a yellow vest AND a baseball cap is a traffic police officer. But, I couldn't say definitely while sitting in the coffee shop that the person standing behind me at the counter was a police officer or not ... at least not yet.
Later, my guess was confirmed. When the person who was wearing the vest was leaving the coffee shop by the entrance at the other end of the store, I overheard another man's voice - apparently joking with the exiting "officer". It sounded like the one joking did not know the "officer" personally - like when you use a more impersonal tone with someone (or when someone is trying to joke with a police officer!).
Now my curiosity couldn't be contained. So I looked out of the front window of the coffee shop expecting to see the man with the yellow vest walk to his vehicle and confirm my suspicions. I saw a man wearing a yellow vest and a baseball cap ... and he was indeed wearing a police uniform too. In addition, although not a marked police cruiser, he did walk up to and get in to a grey, unmarked, American made sedan - just like the cars undercover traffic offense (ie. speeding) officers drive.
Now I could put the rest of the pieces of the puzzle in place - or what the man in the store had spoken jokingly to the police officer as he was leaving. Again, I didn't hear the words of what was spoken, but I can imagine almost exactly what those words were:
Man sitting by entrance: "Which way are you going?
Police officer: "Why?"
Man: "So I know which way to go [in the opposite direction]."