seek a lawyer and send him a LOD.
some people afraid to deal with the law eventhough you didnt have a case to win.
so the dude may chicken out to avoid trouble to hire a lawyer to defend himself.

Next, maybe get a police to help.
imagine a police telling you " kawan saya mahu tidur lena lepas 11 mlm, kalau hang buat bising lg, hang pikir lar sendiri lain kali i dtg".
Most people do not want to cari pasal with police on a personal basis.
Calling police to raid him and getting a police (your friend) to warn him can be 2 different effect.

your statement seems to remind people to be afraid of lawyer or not to mess with lawyer, even though you are suffering.
remember you hire a lawyer yourself.
what makes you think your own lawyer is inferior to him?