ESTHERVILLE, Iowa (AP) — An 18-year-old has pleaded not guilty to a murder charge in the slaying of a 19-year-old man in northwest Iowa. Online court records say Lee Christensen entered a written plea on Monday in Emmet County. He's accused of shooting to death Thomas Bortvit, who also was from the Estherville area. Bortvit's body was found in a rural area of Emmet County on June 7, and investigators have said they think Christensen shot Bortvit on June 6.