Buying tenant occupied duplex

[Lynette P.]

My first post! In escrow to buy a duplex in CA. Both units occupied. Month to month lease. Waiting for seller disclosures. Looks like 1 unit is at/near mkt rate & the other is about $350 below. Once escrow closes, do I go through the same due diligence process as usual - online application w/ background & credit check? Or not because they already live there? Should I have them sign 1 yr lease? Can I (should I) bring rent closer to mkt rate? I assume when there is change in ownership, the 5% annual rent cap doesn't apply. Any advice would be appreciated!