Kathryn Frankel, 41, is charged with arson, criminal mischief, and related counts, said the Chester County District Attorney's Office on Wednesday, July 31.
The fire was "well-advanced" by the time authorities arrived at the 400 block of Leopard Road around 11 a.m. on July 23, Berwyn Fire Company said previously.
Frankel was the only person home at the time of the blaze, and was seen "wandering around the property" before authorities arrived, the DA's Office said. First responders said she was "covered in soot" and had singed hair, according to prosecutors.
A cigarette lighter was located near the house, and a canine team found "ignitable liquids" on Frankel's clothes and in the home, authorities said.
The Fire Marshal's Office has since ruled the blaze "incendiary," meaning intentionally set, the DA's Office said.
Authorities responded to a blaze at the same house on May 1, and will now "review" the investigation into that fire in light of the charges against Frankel, they added.
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