S.F. lawmaker's bill would make it easier to challenge expert testimony as science advances FacebookTwitterEmail JoAnn Parks, left, with her attorney Raquel Cohen after she was released from the Central California Women’s Facility in Chowchilla (Madera County) on Jan. 12, 2021.Courtesy of the California Innocence Project SACRAMENTO — For nearly three decades, JoAnn Parks was imprisoned for killing her three children in a house fire that she said she did not set. Even after advances in scientific understanding of fire behavior undermined investigators’ conclusion that she had committed arson, Parks was unable to win a new trial — which critics argue exemplifies a fundamental flaw in how expert testimony is treated.