You searched for: “trooper
trooper, trouper
trooper (TROO puhr) (noun)
A horseback mounted police officer or a member of a cavalry: "His cousin is a trooper in the local police force who rides her horse during parades."
trouper (TROO puhr) (noun)
An individual who travels with a musical or theatrical group: "A troubadour could also be considered a trouper because a troubadour often traveled with groups of actors."

The trouper used to work with the police and was a trooper in the police band.