U.S. Attorney William Hochul says Dawn Nguyen (new-WHEN') of Rochester faces federal charges of knowingly making a false statement.
She was hit earlier Friday with a state charge of filing a falsified business record.
State Police Senior Investigator James Newell says the charges are connected to the purchase of an AR-15 semiautomatic rifle and a 12-gauge shotgun that William Spengler had with him Monday when firefighters Michael Chiapperini and Tomasz Kaczowka were gunned down.
Three other people were wounded before the 62-year-old Spengler killed himself.
Reached by The Associated Press before her arrest, Nguyen declined to comment. A phone number for her lawyer was unavailable.
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