The lawsuit claims that the company that made the marijuana candy and the store that sold it to Richard Kirk recklessly and purposefully failed to warn him about the bite-sized candy's potency and side effects - including hallucinations and other psychotic behaviors.
Hours after Kirk purchased the marijuana candy on April 14, 2014, his wife, Kristine Kirk, 44, called 911. She said her husband was ranting about the end of the world and jumping in and out of windows at their home in Denver's Observatory Park neighborhood.
All three of the couple's young sons heard the gunshot that killed their mother.
Their youngest son, who was 7 at the time, watched his mother die, according to an amended complaint that was filed on Monday night.
Kirk now faces one count of first-degree murder in his wife's death.
A partially eaten Karma Kandy Orange Ginger candy was found at Kirk's Observatory home after the shooting. The candy - which was roughly the size of a Tootsie Roll - contained 10 servings of THC, with each serving containing about 10 milligrams. THC is the major psychoactive ingredient in marijuana.
Read more here.