Purchase a duplex has a tenant

[Huiping S.]

We are on the process of inspection for a Duplex of NC. One side can check and another side has a tenant with a new 1 year lease contract. 

Except lease contract, statement or evidence of security deposit, move-in check-in list, what other documents should we get from the seller? 

Never handle a purchase has a tenant. What should a buyer pay extra attention for this type of purchase? 

Thanks.

Huiping