GRISWOLD, Iowa (AP) -- A teenager told police she poured 2 gallons of gasoline through the house while her family slept, then set it on fire to get back at her stepfather, who was arrested later for allegedly sexually abusing her.
Tracey Dyess, 17, was charged with first-degree murder, attempted murder and arson in the March 31 blaze that killed her 13-year-old sister and 6-year-old brother.
Her stepfather, Brian Street, 39, and mother, Debbie Street, 37, were awakened by a smoke alarm and escaped the house in this southwest Iowa town.
Brian Street was jailed on 10 counts of third-degree sexual abuse after authorities opened a bedroom safe that Tracey Dyess told them contained photos of her taken by her stepfather. They found 65 Polaroid photos of sex acts and nudity, as well as 35 rolls of undeveloped film, court documents said.
Tracey's mother, testifying Thursday at a hearing for her daughter, denied knowledge of the abuse.
''I didn't know. I didn't know,'' Debbie Street said, sobbing and rocking back and forth. She said her daughter had been sexually abused by other men, starting when she was 4 years old.
Public defender Greg Steensland asked a judge to have Dyess tried as a juvenile, so she can get counseling.
''In this case, the family dynamic is a tragedy that has evolved over years and years, and probably generations,'' he said.
Prosecutors are resisting the motion to have the case heard in juvenile court because Dyess would only serve 18 months before state rules would require her release.
Dyess' grandmother, Diane Street, of Clay Center, Neb., described Brian Street as a controlling man who moved the family every few weeks and would not allow the children to attend school.
''He's been in trouble almost his whole life,'' she said.
He served prison time in Missouri after trying to rob a taxi cab with a BB gun, she said. At the time of the fire, he was wanted on a bad check charge.
Debbie Street, who declined to comment outside the courtroom, is Brian Street's stepsister, as well as his wife.