Occupied Rentals - Tenants

[Brandon Johnson]

Newer to REI. Looking for rented OR tenant occupied duplexes in my area. Has anyone experienced dishonest agents, saying that property is rented when it is not. If they provide a lease, even if it's month-to-month, is that a binding part of the agreement? How does the lease transfer over upon closing. Does the tenant have to sign a lease with me to stay in the property. I'm not looking to change the terms.

I know, several questions. Any help would be appreciated. 

Thanks.