 For Pierce County government, Quinn-Brintnall was chief criminal deputy (1983–86) under prosecuting attorney William Griffies and then senior criminal prosecutor and head of the appeals unit (1986–94) under prosecuting attorney John Ladenburg.In 1994 she moved into the civil division of the Pierce County Prosecuting Attorney's Office.She worked there for six years on a variety of civil topics, including annexations, incorporations, land use, contracts, bankruptcy, elder care, juvenile law, labor law, and privacy issues.