A Falls Church woman who climbed out of her burning third-story condominium last December while her 18-year-old daughter was inside, pleaded guilty yesterday to setting the fire and murdering her daughter.

Gloria Prudencio, 42, initially told fire and police investigators that she had seen a man leaving her apartment when she returned after dropping one of her children at day care the morning of Dec. 22. Only her oldest daughter, Yiti Arevalo, visiting from Honduras, was home.

Prudencio said that Arevalo's bedroom was in flames and that she tried but failed to rescue Arevalo. But as she sat in a hallway at Vencor Hospital in Arlington later that day, she told a different story to her sister-in-law, in Spanish, and a Spanish-speaking officer sitting nearby heard the second version. "Stop crying," Prudencio said to her sister-in-law. "The police are going to think something is wrong," Assistant Commonwealth's Attorney Todd F. Sanders revealed in court yesterday.

At a preliminary hearing in January, Officer Paul Marinero testified that he heard Prudencio say, "I did something very wrong." She later told Marinero she "heard voices telling her to set the apartment on fire, to set Yiti on fire."

Sanders said Prudencio poured a trail of flammable liquid around her daughter's bed and out of the bedroom, then ignited the liquid from outside the bedroom. "She heard her daughter screaming for help," Sanders told Chief Circuit Court Judge F. Bruce Bach. "She opened the door, saw her daughter in flames, shut the door and went to the balcony."

Arevalo also had suffered blunt trauma to the head and a stab wound to the face, but Prudencio said she didn't remember how that occurred, Sanders said. The prosecutor said Prudencio told police "she felt bad and knew she had to be punished."

Prudencio did not make any statements during the brief hearing, in which she entered guilty pleas to second-degree murder and arson. Prosecutors agreed to recommend that the terms be served concurrently, meaning Prudencio faces a possible sentence of five to 40 years without parole.

Arevalo had been raised by her grandmother in Honduras, family friends said. She arrived in Northern Virginia in November to visit her mother and stepfather. Prudencio worked as a nanny, and she and her husband were raising two children, ages 6 and 13.

The fire occurred in the family's condominium at 3100 S. Manchester St., in the Woodlake Towers building. Marinero testified that he also heard Prudencio say that "I saw them in bed together," believed to be a reference to Arevalo and her husband. But police and prosecutors said Juan Prudencio adamantly denied any improper relationship with Arevalo.

Bach scheduled Gloria Prudencio's sentencing for Oct. 29.