If escrow has closed and the former owner does not move out, what rights does the new owner have?

New owner must follow eviction laws. Option: offer to pay occupants maybe $2000 to voluntarily vacate in 30 days and leave in broom swept condition..(that's how much it will cost you to bring unlawful detainer action (eviction) But still serve the 3 day notice to quit immediately so you can start eviction proceedings timely. Google eviction requirements in CA to make sure you do everything perfect. Your unlawful detainer action can ask for damages in the form of rent as well.