A 73-year-old woman was behind about two dozen fires in an Alexandria apartment building over the past 10 months, officials said Thursday.

Shirley Ann Vigneau told authorities Wednesday night that she started 25 fires in a building in the sprawling Southern Towers Apartment complex, said Thomas Faison, a spokesman for the federal Bureau of Alcohol, Tobacco, Firearms and Explosives. She has been charged only in the most recent fire; officials said that could change.

Vigneau used matches to start paper fires in trash rooms, hallways and other public places, usually after midnight, and caused repeated evacuations and about $55,000 in damage, Faison said. She set fire to boxes, newspapers and fliers taped on message boards, authorities said.

“She apparently derived something from these fires, but as far as we know, there’s no economic or ideological aspect to it,” he said.

Vigneau is retired, and she has lived in the building, in the 4900 block of Seminary Road, for more than 30 years, officials said. She lived alone and has no known family in the area.

Shirley A. Vigneau (Courtesy of City of Alexandria)

Zerihun Bedasso, a next-door neighbor, said he was “shocked” to hear that Vigneau was accused of starting the fires. He said she knocked on his door Wednesday to tell him that investigators had come to interview her but gave no sign that she was involved.

Vigneau was caught by a security camera Tuesday night as she went in and out of a trash room as a fire was starting, authorities said. She was arrested Wednesday and, under questioning, admitted to the arson, said Alexandria’s interim fire chief, Andrew D. Snead.

Alexandria’s fire department has been working with the ATF since the fires began in May 2013. The building has more than 450 apartments, and many elderly people and young families live there, Faison said.

“Folks are sleeping well now, sleeping better now, they’re safe,” he said.

It’s “very unusual” for an older woman to set fires, Assistant Fire Chief Rudolph Thomas said; arson by women, in general, is unusual.

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