Educate yourself,
Never open your door to LEO, tell your roommate.
If they demand entry and you don't want them in your home tell them you will dial 911.
Ask if they have a warrant, if they don't and they have no probable cause they are not going to kick your door in.
On the other hand if they do have probable cause they will kick the door in.
Before they do they will threaten to.
Just tell them thru the door that you want to confirm the actions they are taking with a supervisor. Don't open the door....
Turn on shower, turn up music then it's the time to flush, run your disposal.
If you don't have a disposal Get one.
Nothing get rid of weed faster.
Toilets clog....
Now call a lawyer and ask for help and throw that roommate out IMHO.