Every day nearly 7,000 people die in America. And when these deaths happen suddenly, or under suspicious circumstances, we assume there will be a thorough investigation, just like we see on CSI. But the reality is very different. In over 2,000 counties across America, elected coroners, many with no medical or scientific background, are in charge of death investigations. Nationwide there is a severe shortage of competent forensic pathologists to do autopsies. The rate of autopsies -- the gold standard of death investigation -- has plummeted over the decades from 50 percent of those who die to less than six percent. As a result, not only do murderers go free and innocent people go to jail, but the crisis in death investigation in America is also a threat to public health. FRONTLINE correspondent Lowell Bergman reports the results of a joint investigation with ProPublica, NPR, and the Investigative Reporting Program at UC Berkeley.