Prosecutors yesterday said that 36-year-old Alison Michelle Ernst was freed by Las Vegas police after being questioned by US Secret Service agents in the Thursday incident at the Mandalay Bay resort.
As Ernst was taken into custody, she said she threw a shoe and dropped some papers. She didn't say why.
Ernst's jail booking photo shows she wore blonde wig at the time.
Ernst couldn't immediately be reached yesterday. It wasn't clear if she had a lawyer.
Clinton wasn't struck by the shoe. She joked about the incident and continued with her talk to the Institute of Scrap Recycling Industries.