Legal Question in Landlord & Tenant Law in California

How do you know he smokes "drugs" when you have never seen him doing it? Just because he has a pipe you assume he is doing something illegal? If I see you have a gun do I assume you are a killer? He may be a collector of pipes; or he may have a doctor's recommendation to use medicinal marijuana, which is legal under the state law. The fact that you took a picture of his property inside his appartment without his permission is a gross violation of his privacy for which you can be sued.

I suggest you leave him alone and govern yourself accordingly.