Erin Micco, a Florida native who recently lived in Rutherford, was arrested soon after the two-alarm blaze destroyed the 2½-story Pearl Street home and damaged a neighboring residence last Nov. 17.
None of the squatters were injured in the fire, which took nearly six hours to douse.
Micco, who turns 30 this Friday, has a criminal history that dates back to 2012.
She served time for grand theft and trafficking in stolen property in Florida, among other offenses, and was charged in Paterson with making terroristic threats three years ago, records show.
Rather than go to trial, she took a deal from prosecutors, pleading guilty to aggravated arson, Passaic County Prosecutor Camelia M. Valdes said.
Superior Court Judge Joseph Portelli scheduled sentencing for May 14.
Micco, meanwhile, remained held in the Passaic County Jail.
Assistant Prosecutor Timothy Kerrigan is handling the case for the state.
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