A doctor says a Colorado man accused of killing his wife after eating marijuana-infused candy bought at a legal pot shop was experiencing psychotic-like symptoms due to the drug.

The doctor's findings are contained in recently filed court documents in the case of 49-year-old Richard Kirk, who is charged with first-degree murder in the April 2014 shooting death of his wife, Kristine. Police say he ate the candy, then shot her while she described his erratic behavior on a 911 call.

He pleaded not guilty by reason of insanity on Friday.

The doctor, Andrew Monte is a defense witness. He says Kirk was intoxicated with THC, the drug's psychoactive ingredient, which led to delirium.

Prosecutors say Kirk and his wife had been fighting over marital and financial problems.