First off who cares what he tells other people? AS Im sure you already know life isnt a popularity contest and people will talk about you behind your back everywhere you go. Ignore it and move on.
Secondly let him keep calling the police. If the complaints are unfounded and you arent getting in trouble who cares. Eventually the police will get tired of sending officers for fruitless complaints and he will be spoken to.
“Take you hands off the car, and I’ll make your birth certificate a worthless document." UNKNOWN