LOS ANGELES (AP) — A judge has ruled that two alleged gang members charged in the robbery and killing of an off-duty Los Angeles police officer will remain in federal custody without bail. Officer Fernando Arroyos was fatally shot at about 9:15 p.m. Monday in an unincorporated area of south Los Angeles County that is in the territory of the Florencia 13 gang. The suspects allegedly targeted him because of two silver chains around his neck. Prosecutors have filed federal charges against three alleged gang members and one associate. Two of the defendants are scheduled to return to court later this month, while the alleged gang associate is expected to be in court on Tuesday. The fourth defendant is in the hospital.