Legal Question in Criminal Law in California

Entering a building unlawfully with the intent to commit a crime inside is burglary. (This is the basic definition; it varies somewhat from state to state. For example, in some states the intended crime has to be a felony, while in others it can be a misdemeanor. Some states also limit it to illegal entries that happen at night -- which was the original standard even though most states no longer follow it.) The crime doesn't have to involve theft, and the burglar doesn't even have to go through with it. What matters is whether he intended to do it at the time of the illegal entry.

Entering the building is all it takes, as that implies intent unless you can prove a lawful reason.