Plane met by police on arrival, but no handcuffs or commotion?

I landed at JFK from a domestic flight that was uneventful as far as I know. The crew told us to stay seated for 2 people to deplane first. Naturally I thought they had a short connection.

But on arrival at the gate, the pilot didn’t turn off the seatbelt sign. A police officer boarded the plane. Then two passengers deplaned with him. But, there was no indication during the flight anything was awry. The passengers were not in handcuffs or any visible form of distress.

Anybody care to speculate what happened?