OAKLAND, CA - AUGUST 11: Bay Area Rapid Transit police officer Jason Ledford patrols with his bomb-sniffing dog Andy at the Oakland Coliseum station August 11, 2005 in Oakland, California. BART remains at a heightened state of alert following the recent London Underground bombings and is preparing to launch a poster campaign in its stations that encourage riders to report suspicious packages and activity. (Photo by Justin Sullivan/Getty Images)
