John Roll
On June 23, 2011, President Obama nominated Zipps to a seat on the United States District of Arizona, to replace Judge John Roll, who was killed in the 2011 Tucson shooting. On September 8, 2011, the Senate Judiciary Committee reported her nomination to the Senate floor by voice vote. The United States Senate confirmed Zipps by unanimous consent on October 3, 2011. She received her judicial commission on October 5, 2011.