Death and the science of it have dominated Peerwani’s 30-year career in the Tarrant County medical examiner’s office. Now, Peerwani is taking on a very live controversy as chairman of the Texas Forensic Science Commission: the continuing investigation into the arson science that led to the conviction and 2004 execution of Cameron Todd Willingham.

“His background and his temperament give him the unique ability to make sure the commission is focused on the science of forensics ...