A Baltimore man will spend at least nine years in prison for his part in impeding a federal drug investigation. Prosecutors from the U.S. District Attorney’s office say 36-year-old Mark Johnson helped his brother, Christopher Johnson and others, attempt to hamper an investigation into a drug-related triple murder. The deaths happened seven years ago in a barn in Franklin County. The three victims were found with their hands zip-tied behind their backs and were set on fire. One of three had been a drug informant to federal officials in Hagerstown.