I was the only real cop on the force.
This was like being the only cop in a big city.
But you are the only cop I've ever met who has so much experience in tracking down serial killers.
It's pretty much the only cop show that I would do.
"Why do you think an old woman's the only cop on Kolya?"
"You're not the only cop in the world, you know."
"I'm the only Jewish cop anywhere around here, so I had to stop by and check it out."
Perry was the only cop I knew who would be gracious even over the bloody remains.
The only cop without a stack of active cases on his or her desk was me.
"Twenty-three's not so many," said the only experienced cop in the room.