A California landlord can file an unlawful detainer complaint by completing and filing various required forms with the county Superior Court where the property is located. These forms include a Summons, Complaint, and Civil Case Cover sheet. The court keeps the original documents and will provide the landlord with a copy to serve on the tenant. In order to make sure the service of the Summons and Complaint is properly completed. we always suggest that the service be completed by a registered process server.