A woman has been charged with buying two of the weapons that William Spengler Jr. used in the Christmas Eve shooting of four volunteer firefighters.

Dawn Nguyen, 24, was with Spengler when she bought the guns for him in 2010, the charge alleges.

Two-and-a-half years later, the guns were among those Spengler used in his brutal ambush of first responders that killed two men, wounded three others and burned down seven houses in Webster. Another body was found in the ashes, believed to be that of Spengler's sister Cheryl.

Around 1:40 p.m. Friday New York State Police, Webster Police and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives descended on the Alpine Road home where Dawn Nguyen was staying.

Nguyen, who once lived next door to Spengler on Lake Road, was taken out of the home in handcuffs.

Nguyen's charges include a state count of first-degree falsifying business records, a class E felony. She is scheduled to appear in Henrietta Town Court at 5 p.m. Jan. 8.

At an afternoon news conference in Rochester, U.S. Attorney William Hochul Jr. said Nguyen is charged with lying when she purchased two weapons - a .223-caliber Bushmaster rifle and a 12-gauge Mossberg shotgun - allegedly on behalf of Spengler.

Spengler was with Nguyen, a former Lake Road neighbor, when the weapons were purchased at the Gander Mountain sporting goods store in Henrietta on June 7, 2010, Hochul said. The rambling letter Spengler left behind, which Hochul described as a "suicide note," informed authorities that the guns had come from the daughter of a neighbor.

Hochul and others at the afternoon news conference described Nguyen's alleged actions as a "straw purchase," in which one person intentionally and knowingly buys guns for another. Spengler could not legally own or purchase guns because of a felony conviction: he bludgeoned his grandmother to death in 1980.

The felony with which Nguyen is charged carries a sentence of up to 10 years in prison and a $250,000 fine.