Eight years after his father died at a Chillicothe, Mo., hospital, David Gann learned from lawyers that they suspected Coval Gann and several other patients were murdered. So the younger Gann in 2010 filed a wrongful-death lawsuit. He and four other plaintiff families alleged that Hedrick Medical Center for years failed to notify deceased patients relatives about the suspicions expressed by some hospital employees during a rash of deaths in 2002.