Are these sentences correct?

I am doing some kind of survey about the negative polarity items.

Could anybody please let me know whether these sentences are correct or not?

only one cop who has ever arrested the notorious criminal smokes
only one cop has ever arrested the notorious criminal

And if you think these sentences are not correct, could you explain why?

Thanks in advance.

[Casiopea]

Originally Posted by Could you..

negative polarity

Hint: there's a subject problem.

Repair #1 (add in existential "there" and conjunction "and")

There's only one cop who has ever . . . and s/he smokes.


Repair #2 (delete "who" and add in conjunction "and")

Only one cop has ever . . . and s/he smokes.