I’m sure the Chief looked at his reports and saw that very unique “g” in them matching the hand writing?
People don't just steal money, they run off with all sorts of food or sleeves of cups or whatever. And some people will banging each other in the drive through if they aren't afraid of being caught...especially underage employees working their first boring job.
So the police chief knows because (as an earlier article mentioned) the store owner reviewed the camera footage and there was no note written on the receipt when the food was handed to the Officer.
Mine still makes for a better story. /h