The inverse of this was common practice in Cleveland, OH when I lived there from 1964 to 1968.

Remember that this was before cell phones, caller ID, and all the police carrying radios when they exited their patol cars.

Residents in the gheto learned that a call to the police commonly went unanswered for hours especially on Sat night. They took to calling and telling the dispatcher that an officer was down and hanging up.

Of course, the Cleveland Plain Dealer decried this practice.