Legal Question in Criminal Law in California

You're mashing legal terms and standards together.

There are different levels of police interaction:

Consensual encounters - no legal justification is necessary for an officer to speak to anyone as long as the officer is in a place they have a lawful right to be. The person must be free to leave and not cooperate.

Detention - they need reasonable suspicion of criminal activity to detain somebody. Just being in a location, by itself, doesn't sound like enough to justify a detention. They can ask questions during a detention without advising you of your rights.

Arrest - they need probable cause.

For more about police interaction, see the link below:

www.joedane.com/featured/interacting-with-the-police/