By Steve Tawa

PHILADELPHIA (CBS) — A fire expert in private practice has testified about his forensics analysis of an Oxford Circle rowhome fire 31-years ago that killed two young brothers, ages three and four. Now, their father is being retried on murder and arson charges.

Thomas Schneiders, hired by the DA’s office to review the original fire marshall’s report of the 1985 fire that killed the defendant’s two little boys, says there’s no way it was caused by a flashover condition as the defense claims.

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That’s when heat and smoke get trapped by a ceiling and at a certain point, 1,100 degrees, everything flammable in a room ignites.

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Schneiders points to a chair near the front window where a fire would naturally migrate. He says it would’ve been consumed, but it was not.

After looking at evidence, documents, and photographs, he backs the original finding that three, v-shaped burn patterns from the couch, loveseat, and table clearly show it was intentionally set in three places.

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Fifty-six-year-old Daniel Dougherty was convicted and sentenced to death in 2000, but he was granted a new trial by an appeals court.