LAS VEGAS -- Federal authorities have lodged two criminal charges against a Phoenix woman accused of throwing a shoe at Hillary Rodham Clinton while she gave a convention speech at a Las Vegas Strip resort.
Alison Michelle Ernst, 36, didn't respond to a phone message Monday about the charges of trespassing and violence against a person in a restricted building, which were filed Sunday in U.S. District Court in Las Vegas.
She could face up to a year in federal prison on each charge if she's convicted.
A court date wasn't immediately set, and it wasn't clear if Ernst had a lawyer.
Las Vegas police booked Ernst last week on a misdemeanor disorderly conduct charge and freed her with a June 24 court date. Charges haven't been filed in that case.
A disorderly conduct conviction could get Ernst up to six months in county jail.
Ernst immediately surrendered and was arrested after the incident Thursday in a ballroom at the Mandalay Bay resort.
The federal charges accuse her of bypassing security to enter the ballroom and committing a violent act by throwing the shoe that police say she pulled from a purse and hurled about 60 feet toward the former secretary of state.
Clinton expressed surprise but wasn't struck by the shoe. She made a couple of jokes and continued her speech before more than 1,000 people at a recycling industry conference.
An orange-and-black athletic shoe was recovered from the stage.
Ernst acknowledged throwing a shoe but didn't explain her actions to reporters as she was taken into custody by the U.S. Secret Service.
The incident reminded some of an Iraqi journalist throwing shoes at former President George W. Bush during a Baghdad news conference in December 2008. Shoe-throwing is considered an insult in Arab cultures.
Clinton has Secret Service protection because former presidents and their spouses are covered for their lifetime, said Brian Spellacy, head of the U.S. Secret Service office in Las Vegas.
Clinton, the former first lady and Democratic senator from New York, has been giving paid speeches to industry organizations and Democratic Party groups around the country. She has said she's considering a presidential bid.