Her dad had given her a gun for protection.
Police in Cheyenne, Wyo. say the bullet went through a chair, into a wall and narrowly missed several customers.
There were officers in the coffee shop when the gun went off.
The 17-year-old had received the gift from her dad for Christmas. He encouraged her to carry it so she'd be safe.
Police gave her a citation for underage possession of a firearm.
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