Editor's note: The above video is from a Wednesday newscast. 

PHOENIX (AP) — Bill Montgomery has resigned as Maricopa County's top prosecutor as he prepares to take a seat on the Arizona Supreme Court.

Montgomery submitted his resignation on Thursday, a day after Gov. Doug Ducey announced he'll appoint Montgomery to the high court. His departure is effective immediately.

PREVIOUSLY: Gov. Doug Ducey appoints Bill Montgomery to Arizona Supreme Court

Chief Deputy County Attorney Rachel Mitchell will run the office until the Republican-controlled Board of Supervisors appoints a replacement to serve through the 2020 election.

Mitchell is known for questioning Christine Blasey Ford a year ago about her sexual assault allegation against then-Supreme Court nominee Brett Kavanaugh.

RELATED: Maricopa County Attorney Bill Montgomery accused of ethical misconduct