The Department of Homeland Security has rejected a call from its internal watchdog office to suspend or end security details for the heads of two of its most significant components: Customs and Border Patrol and Immigration and Customs Enforcement.In a report released Thursday, DHS Inspector General John Roth said there's no clear legal authority for the executive protection arrangements and a perception they may have little to do with mitigating any real threat."Because these security details incur substantial monetary and personnel costs, provide transportation and logistical services not necessarily tied to any demonstrated security concern, and are often authorized by those receiving the services, these details give the appearance to some observers of being more related to executive convenience and status than protection," Roth wrote.