DENVER – The family of three boys filed a lawsuit against two recreational marijuana businesses after a shooting that left their mother dead and their father charged with murder.

The lawsuit claims companies that made a type of marijuana-infused candy and sold it to the father failed to warn him about its potency and possible side effects, including psychotic behavior.

The Denver Post reported Tuesday the suit was filed on the boys’ behalf by their grandparents, Wayne and Marti Kohnke, and aunt, Tamara Heman, who are now their guardians.

Richard Kirk is charged with first-degree murder in the April 14, 2014, shooting death of his wife, Kristine Kirk. Before she was shot, Kristine Kirk told a 911 dispatcher her husband was hallucinating and was getting a gun.

Richard Kirk pleaded not guilty by reason of insanity. A defense expert, Dr. Andrew Monte, said in a report submitted to the court that Kirk was intoxicated with THC, marijuana’s psychoactive ingredient, which led to delirium.

Authorities said low levels of THC were found in his blood, and a partially eaten piece of marijuana candy was found in the house. The candy came from a legal marijuana shop.

The lawsuit names Gaia’s Garden LLC and Nutritional Elements Inc. It says Gaia’s Garden made the candy and that Kirk bought it from Nutritional Elements.

Sean McAllister, an attorney for Gaia’s Garden, said the company has always complied with state requirements for labeling and packaging its products. He said marijuana doesn’t lead to violence and that the company will fight the suit.

Tiffany Goldman, chief operating officer for Nutritional Elements, declined to comment.