A man has been convicted of attempted murder for attacking a teenager with a medieval battle ax.

Scott Tyler Stapley, 22, was convicted by a jury in 3rd District Court on Wednesday.

Prosecutors say that in July Stapley assaulted a 17-year-old with a four-bladed warrior ax with a spiky ball attached.

Defense attorney Scott Wilson said a friend of Stapley's, Cody Jesse Augustine, 21, believed the teen was the source of an STD Augustine got from a girlfriend. Wilson said Stapley initially went along for the confrontation as a lookout.

Stapley said Wednesday he was acting in self-defense after the teen ran toward him while trying to get away from Augustine, who also is charged with attempted murder and has pleaded not guilty, according to court records.