According to reports, Alec Eric Arapahoe arrived to his grandparents house smelling of alcohol.
The report indicates one of his family members asked him to turn over his stun gun since he appeared to be drunk.
That's when police say Arapahoe became angry. His grandmother and her sister tried to leave, but they say he became more angry, grabbing them and taking their cell phones.
Eventually, police say Arapahoe fired his stun gun at the wall directly behind the two women.
With no cell phone, his 66-year-old grandmother attempted to run out of the home. As she was running out, officers say Arapahoe fired the stun gun, hitting her in the back.
She was still able to run out of the home and call police.
Police arrested Arapahoe nearby, and found a stun gun probe and other evidence with him.
Arapahoe is facing charges of third-degree assault, use of a stun gun, and false imprisonment. He is begin held in the Boulder County Jail.
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