If a security officer is assigned to work a private party and someone uninvited refuses to leave, what can the officer do?

The correct action for a security officer in this scenario is to call the police. While arrest for trespass is a potential legal remedy, it is typically beyond the authority of most security officers, especially if they are not certified peace officers. The role of a security officer is to protect property and ensure the safety of guests, but making an arrest can lead to complications and could expose the officer to legal liability if not done properly.

Calling the police is the most effective and legally sound option in this situation. The police have the authority to enforce the law and handle situations involving trespassing. They can remove the uninvited guest and address any potential threats to the event's security, allowing the security officer to focus on ensuring the safety of other guests and managing the event.

Using physical restraint may also seem like a tempting option in order to remove the individual, but security officers are generally trained to avoid physical confrontation unless absolutely necessary, to minimize risk to themselves and others. Ignoring the intruder is not a responsible choice, as it can lead to escalation of the situation and a potential security risk for other party attendees.