Kristine Kirk, 44, told 911 dispatchers Monday night that her husband had ate pot candy and taken prescription pills before starting to hallucinate.
Mrs Kirk died about 12 minutes into her call after telling dispatchers that her husband Richard Kirk, 47, had retrieved a gun and a shot was heard.
Before she was shot, Kirk could be heard in the background talking about the marijuana products he legally purchased earlier in the day.
Investigators later found a receipt from a dispensary, showing Kirk purchased items including an edible called 'Karma Kandy Orange Ginger'.
A Colorado company makes a product with the same name and warns on its website: 'A single bite is enough, even for those with intense medical needs'.