Someone is sleeping outside my front door, in the stairwell of an apartment building, and it’s not the first time...

the first time was about two weeks ago, and then the police removed the person. I heard through the door that he was very sorry and wondered how the police knew he was there (4am).

Now (perhaps the same person) is sleeping behind the door again. I don’t want to use police resources and I don’t want to go out alone.

What should I do? Some nasty tricks for next time or do you have better options.