(Cass Co., NE) -- An 18-year-old is charged with first-degree murder in Cass County. Jabari Parsons is accused of stabbing 55-year-old Mary Blackwell to death at a home near Plattsmouth Thursday afternoon. The Cass County Sheriff's Office says deputies were called to Blackwell's home to investigate a fire. That's where they say they found Blackwell dead and Parsons in her living room.