Anyone ever evicted squatters based on trespassing?-

[Ed B.]

I'm in California, just bought a house with squatters  in  it who were supposedly allowed to stay there by the former owner while they did cleaning, etc.   I've been told I need to give a 30 day notice before I can file eviction. However, there appear to be two situations in which I can evict after giving only a 3 day notice to quit:  Trespassing, and causing a nuisance (local police will vouch for the latter). California code 602 (o) appears to define trespassing as not simply entering without permission (which you could argue they didn't, because the former owner gave his permission), but remaining on the property after being asked to leave. They have  been asked, and refused.

I think I have grounds to evict on only the 3 day notice, but am slightly worried the judge may disagree and tell me I can only evict after a 30 day notice. Anyone had any experience  with something similar who can chime in with their thoughts? Thank you!