They call themselves sovereign citizens, and they're part of a growing anti-government movement that rejects state and federal law. The Southern Poverty Law Center tracks extremist groups and estimates there are 300,000 sovereigns nationwide, but a NewsChannel 5 investigation reveals the movement is thriving here in middle Tennessee. The Southern Poverty Law Center is warning police departments across the country about the growing movement. It has produced a video which shows officers how to identify sovereigns. In May, two men who belonged to the movement, shot and killed two West Memphis police officers after the officers pulled them over for...