I think nowadays if I were to mention the show Police Squad! most people wouldn't know what I was talking about. However, if I were to mention the Naked Gun movies, I'd probably get an "Oh! I've seen those!" from a few people.
Much like Mel Brook's television series When Things Were Rotten (you might not remember that) would find a second life as Robin Hood: Men in Tights (but that you might remember), the series Police Squad! would ultimately find new life and success as the Naked Gun movies.
Police Squad! was just one of those shows that just wasn't appreciated in it's time. Produced by the Zucker Brothers and Jim Abraham who had success with movies like Kentucky Fried Movie and Airplane somehow just could not manage that same success on television with that same formula. Cancelled after six episodes due to either an unreceptive audience that just didn't take to their style of satire or television exec's that were just plain stupid.
I'm going with the second one.
The show was the first time we would see Leslie Nielsen in the role of Lt. Frank Drebin. A role he would reprise in the three movies. The series parodied the entire genre of police shows as well as the whole television format in general even announcing that the series was "In Color" during the opening credits. This was a spoof of something television shows used to do in the 1960's when shows were predominantly in black and white and color was still new. So needless to say this was used ironically.
Another particularly funny running gag at the end of every show they would have a freeze frame of the characters in the style of TJ Hooker about to laugh and doing something like pouring coffee.
Of course it wouldn't actually be a freeze frame so the coffee would start spilling out of the cup.
Some of the gags and supporting characters from the series would also find new life in the movies. And since movies have a bit more freedom from censorship than television did back in the day, they could get away with a bit more "racy" humor than the series did.
Just another example of a show ahead of its time and the powers that be just did not "get it".
The complete series is out and relatively inexpensive on DVD. So if you're curious, I'd highly recommend you check it out.