A fire expert says an arson investigation that led Texas to execute a man was poorly conducted and couldn't be supported by science or investigative standards.

Cameron Todd Willingham was executed in 2004 for setting fire to his Corsicana house, killing his 2-year-old daughter and 1-year-old twins.

The state-funded report released Tuesday from fire scientist Craig Beyler mirrors the 2006 findings of experts hired by the Innocence Project.

Beyler's report said "the investigators had poor understandings of fire science."

The Texas Forensic Science Commission requested the report. Chairman Sam Bassett says his panel's final report on the Willingham case will likely be issued next spring.

At Willingham's trial, a fire marshal testified that the accelerant, possibly lighter fluid, was placed in a way to impede any rescue efforts.

At his trial, neighbors said Willingham, the lone survivor of the blaze, was outdoors even before flames engulfed the house and was worried about his car catching fire. Prosecutors contended that he just wanted to get rid of his children, 2-year-old Amber and 1-year-old twins Karmon and Kameron.

Willingham did not testify in his own defense but long contended — even in the moments before his execution — that he was innocent.

Willingham suggested several possibilities for the fire: A lantern lamp dumped fluid when a shelf collapsed inside the house, his oldest daughter accidentally set the blaze, or someone wanted to kill him and his kids.