Marijuana smells in a 4 unit multifamily

[Edgar Perez]

Hello BP,

I own a quadplex 4 unit multifamily in a state where marijuana is not legal in any capacity (recreational or medicinal); and one of my tenants (A) has mentioned marijuana smells coming in through the vents shared among all units.  This is a recent complaint as we just moved in a new tenant (B) and prior to, there were no such mention of this issue.  Any advice on what I can or should do in this situation?  I know without hard evidence I can't make conclusions or accusations to tenant B, and at the end of the day can't control what individuals do, but is there anything I could do to maybe address or deter the issue?

Thanks in advance.