Authorities say a safe in the burned-out home of a western Iowa family held more than important documents — it held incriminating evidence. According to district court documents released in Cass County Monday, hours after setting the fire that killed two children at a home in Griswold March 31st, 17-year old Tracey Dyess confessed to investigators that she started the blaze in order to harm her stepfather. According to Dyess, 39-year old Brian Street had been sexually abusing her for over three years. The proof, she said, was in the family’s safe located in the home’s master bedroom. After executing a search warrant, officials opened the safe and discovered 65 sexually explicit Polaroids of the teen, 35 roles of undeveloped film, five pairs of underwear, and two separate boxes of checks for persons not living in the home. The day after the fire, Dyess was arrested for two counts of first-degree murder, two counts of attempted murder and one count of first degree arson. Street was arrested for ten counts of third-degree sexual abuse. Arraignment for both is set for May second.