The head of a Texas panel reviewing the case of a man who was executed for setting fire to his home and killing his children say the panel doesn't believe arson investigators committed negligence or misconduct.

Texas Forensic Science Commission Chairman John Bradley said Friday that the four-person panel has found insufficient evidence to establish that arson investigators botched their 1991 investigation of the fire that killed Cameron Todd Willingham's three children.

The findings are preliminary and a final report will be presented at a commission meeting later this year.

Investigators concluded that Willingham used accelerant to set fire to his Corsicana home. He maintained his innocence up to his 2004 execution.