MERRILL, Iowa (KCAU) — An 83-year-old Merrill man charged with murder in the shooting death of his stepson has been ruled incompetent to stand trial.

According to a court document filed by Judge Duane Hoffmeyer, Thomas Knapp has been ruled incompetent to stand trial after the court found Knapp to be “suffering from a mental disorder which prevents the defendant from appreciating the charge, understanding the proceedings, or assisting effectively in the defense.”

As a result of the ruling, criminal proceedings are suspended until Knapp has his competency restored. The filing said Knapp should be placed at the Iowa Department of Corrections, Iowa Medical and Classification Center to regain competency, with the facility to provide the court with progress reports.

Knapp is charged with first-degree murder and willful injury in the death of 51-year-old Kevin Juzek in Knapp’s Merrill home.

Knapp shot Juzek with a 20-gauge shotgun through a bedroom door, then deliberately shot him again in the chest.