In 2003, the body of a pregnant, teenaged informant was found along the banks of the bucolic Shenandoah River. She\'d been repeatedly stabbed - her head nearly severed. Brenda Paz had been supplying the authorities with first-hand accounts of MS-13\'s operations. Paz had been one of 3,000 MS-13 members in the Washington, DC area. The increasingly violent and fast-growing gang operates from the sleepy, middle-class suburbs ringing the city.