A Denver man who claimed that eating marijuana-infused candy led him to kill his wife was sentenced Friday to 30 years in prison in a case that helped raise concerns about the potency of pot edibles.

Richard Kirk initially pleaded not guilty by reason of insanity in the April 2014 shooting of Kristine Kirk at their home. The 50-year-old pleaded guilty in February to second-degree murder but his lawyers still sought lenience on the grounds that he had been intoxicated with THC, marijuana's psychoactive ingredient.

Kristine Kirk told a 911 dispatcher her husband was hallucinating and was getting a gun after eating pot candy. Investigators have said the couple also had money problems and note that Kirk still had the wherewithal to remember the code to a locked gun safe.