CHAMBERLAIN, S.D. (AP) — Trial has been delayed for a father and son accused in the January shooting of a Highway Patrol trooper.

Judge Bruce Anderson has approved a mental health exam for 42-year-old Donald London, of Kimball. The Daily Republic reports Anderson also agreed to delay the June trial so the evaluation can be completed. A new date wasn't immediately set.

London is charged with two counts of attempted murder and three counts of aggravated assault against a law officer. He has pleaded not guilty by reason of insanity.

Prosecutors allege London fired a rifle and struck Highway Patrol Sgt. John Koenig when troopers surrounded his house after he threatened to kill the Chamberlain police chief. Koenig survived.

London's 66-year-old father, Michael, has pleaded not guilty to aiding and abetting the crime.

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