Legal Question in Real Estate Law in California

Trespassing has several meanings under California state law. First of all, California law recognizes the common law doctrine of trespass in civil law. If you are walking down a sidewalk and stick your arm over someone's fence, that is trespassing. The common law phrase was Quare Clausum Fregit, which meant "wherefore he broke the close." Damage is not required, and a party can sue to have the other person removed, or an injunction issued to prevent future trespass, and can receive nominal damages of a dollar, even though no damage occurred.

Criminal trespassing is different. The police enforce what are known as the criminal laws, which are also called public offenses. In California, trespassing is defined in Penal Code section 602. You can read that section here: http://law.onecle.com/california/penal/602.html

As you can see from the code section, it takes more than just sticking your arm over the fence for criminal trespass. The police will arrest someone that they are clear is a burglar, but if it is in doubt as to who the true owner of the premises are, they may not arrest and will often say that it is a civil matter.