Thompson said she had suffered facial fractures after strangers beat her at Cheyenne's Martin Luther King, Jr. park last weekend.
She said she couldn't get a room at a homeless shelter and decided to rob the bank Wednesday because she could no longer stay on the streets, court records say.
She faces a detention hearing Tuesday on a bank robbery charge and doesn't have an attorney yet.
FBI Special Agent Tory Smith said in court documents that Thompson entered the US Bank branch off of Carey Avenue and handed a teller a cardboard note that said, "I have a gun. Give me all your money."
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