AUSTIN – Gov. Rick Perry, who upended the Texas Forensic Science Commission last week on the verge of an important hearing into questionable evidence used in an execution, named his final two replacements to the board Friday.

Fort Worth attorney Lance Evans and Bexar County chief medical examiner Randall Frost will fill the two remaining slots after the governor appointed them to the nine-member commission. Under state law, Perry needed to select a defense attorney and a medical examiner to serve on the board, which explores cases in which expert testimony or forensics might have been used in questionable ways.

The commission became funded and operational in 2007 and since has established protocols and sifted through a backlog of cases, concentrating on a couple, including the capital murder case of Cameron Todd Willingham.

Willingham was convicted of setting fire to his Corsicana home a few days before Christmas 1991, killing his three children. He was executed, still proclaiming his innocence, in 2004 after Perry reviewed his case.

Arson specialists, some recruited by the national advocacy group the Innocence Project, studied his case and said the evidence used to prove that Willingham had spread accelerants, such as lighter fluid, were based on now-discredited beliefs about fire and accelerants.

The Texas Forensic Science Commission hired its own independent expert, noted scientist Craig Beyler, who declared in a report last month that no credible evidence of arson existed.

Two days before Beyler was to present his report to the commission, Perry removed the chairman, Austin defense attorney Sam Bassett, and three others, despite letters from four commission members asking that their colleagues be reappointed.

Perry named two replacements at the time, including Williamson County District Attorney John Bradley, whom he named chairman. Perry said that the members' terms had expired and that he was following normal procedures in naming highly qualified replacements.

Bradley, citing the need to catch up with the commission's work, canceled the Beyler meeting. He has since said he wanted all vacancies filled, time to assess the commission's process and goals, and a chance to meet with its members before moving forward.

Evans said he learned of his appointment Friday afternoon and will need time to educate himself on the commission's work. He said he was familiar with the Willingham case only through news accounts.