POTOSI, Mo. (AP) — A Missouri prosecutor is seeking to vacate the conviction of a man who spent nearly two decades behind bars for the 1998 death of his mother — a crime he and others insist he did not commit.

The Kansas City Star reports that Washington County Prosecuting Attorney Joshua Hedgecorth has asked a judge to set aside 38-year-old Michael Politte’s second-degree murder conviction. Politte was just 14 when Rita Politte died in a fire at the family home in the eastern Missouri town of Hopewell.

The Midwest Innocence Project and the MacArthur Justice Center have worked to exonerate Politte, saying he was convicted based on debunked science and a biased investigation. Politte was released on parole last month.