The Torrance Court serves the entire South Bay of Southern California.  Most arrests by the El Segundo police are sent to the LAX Courthouse, however, many times the arrest may take place in Manhattan Beach when an El Segundo officer follows a DUI driver from one city to the next and the arrest takes place in the Torrance Judicial District.  According to one very local El Segundo DUI Lawyer, both agencies work very closely with one another and many ESPD cases are litigated in the South Bay Court on maple, usually in Div. 2 of the courthouse.  When the case is sent to that court the Los Angeles County District Attorneys office will prosecute the matter.  Incidentally, there is no law that prohibits a police officer from making an arrest in a city that is outside their own jurisdiction.  The arrest is considered legal as long as the officer investigating is trained and is certified under POST standards.  In sum, whether the arrest occurs in the city of El Segundo or an adjacent municipality, the case can and will go forward so speak to a local attorney for specific advice about your case.