A review of "Murder Capital of the World," a low-budget documentary that provides a sobering account of drug-cartel violence in Juárez, Mexico, including the sobering statistic that more than 50,000 murders have occurred in Mexico since 2006.We've all seen the news reports: Across the border of El Paso, Texas, the city of Juárez, Mexico, has become a war zone where bloodbaths are a daily routine. As Mexican drug cartels continue their deadly campaigns of narco-terrorism, it quickly becomes clear why Charlie Minn's film is titled "Murder Capital of the World." The film is rife with news clips and staggering statistics,...