One would call "Decoy" for what it is... a female "Dragnet", with the beguiling Beverly Garland ("My Three Sons", "Scarecrow and Mrs. King") and the city of New York filling in for Jack Webb and sunny Los Angeles. But once you get caught in its premise, it's easy to overlook other aspects of the show. Such as the fact that Ms. Garland is required, in her role as undercover policewoman Patricia "Casey" Jones, to play a different role in each of the 39 episodes filmed. In one episode, she could play an exotic dancer in a carnival, in the next, she can play an addict, and so on and so on, all in the guise of a crime fighter. Whether Angie Dickinson, as Pepper Anderson - "Police Woman", took her cues from Beverly Garland is open to debate, but it's clear to say that Ms. Garland's Casey Jones is clearly a trailblazer for other lady lawmen to follow.
As for the other co-star, New York City... "Decoy" isn't the first series filmed on location in the Big Apple, nor was it the last, but it was certainly one of the most effective in terms of its film noir look and fully fleshed characters. This isn't "Naked City", but it's as close a similarity as you can get on a shoestring budget. And it does the city justice, as "Naked City" would do the next year. Check it out on DVD when you get the chance.
"Decoy" is a Pyramid Production in association with Official Films, Inc. with technical assistance from the Policewoman's Bureau, NYC Police Department. 39 episodes were filmed on location in 1957.