COLUMBIA, Mo. (AP) — The scientific work of a former Boone County medical examiner and University of Missouri pathology professor is being challenged by five of his colleagues as a Kirksville man seeks a new trial in a woman’s 1997 drug-related death.

Former medical examiner Jay Dix’s ruling that Wendy Wagnon died from suffocation led to the 1999 Adair County convictions of both Jessie McKim and his uncle, James Peavler. Each was found guilty of first-degree murder and sentenced to life in prison without parole.