Alarid...... while serving in the Army and the Marines, including two tours in Iraq, and returned to Southern California to fulfill a goal of serving in law enforcement. But, early last year, after just a few months as a customs inspector, he was waving in trucks from Mexico carrying loads of marijuana and illegal immigrants. He pocketed some $200,000 in cash that paid for, as far as the government could tell, a $15,000 motorcycle, flat-screen televisions, a laptop computer and more. Some investigators believe that Mr. Alarid, 32, who was paid off by a Mexican smuggling crew that included several...