Duplicate Keys - Who's responsible

[Jason Sand]

Hello, I was notified by a tenant that she wants another mailbox key - ie a duplicate. I gave her one key for the mailboxes and two for entry into the unit. The reason I'm resisting this is because I found out that she was having other people live with her that weren't on the lease for extended time. This particular person is now in jail the last I heard. There have been other things that I just do not trust her this point. More than likely she probably lost the mailbox key and not telling me she did, or she is having someone else picking up their mail there and using that address. To say the least she is a problem tenant.

How would you handle this?