[12] Mitchell spent 12 years in charge of the sex-crimes bureau, which prosecutes crimes including adult sexual assault and child molestation.

[14] Mitchell has overseen and assisted in prosecuting some high-profile sexual assault cases in Arizona, including ones against churches, youth camps, law enforcement, and members of clergy.

[15][16][17][18] In her position in Maricopa County, she has advocated strengthening sex assault laws in the state and has pushed for changes in the courtroom to comfort victims testifying in abuse cases.

Mitchell made headlines in 2016 after allowing a golden retriever mix named Sam to assist children when they were testifying about traumatic episodes.

[22] In September 2018, Mitchell took a leave of absence from the Maricopa County Attorney's Office in order to serve as Investigative Counsel for the Senate Judiciary Committee, during the confirmation hearings of Brett Kavanaugh for Associate Justice of the Supreme Court of the United States.

[28][29] On September 29, 2018, and October 6, 2018, Mitchell was portrayed by actress Aidy Bryant in the Saturday Night Live opening sketch, and referred to in the "Weekend Update" segment.

[4][33] Mitchell got the job after Montgomery's longtime chief deputy Mark Faull left on medical leave and his replacement Michael McVey was accused of having an inappropriate relationship with another county employee.

[34] Mitchell, along with Jon Eliason, Allister Adel, Rodney Glassman, John Kaites, Gina Godbehere, Chris DeRose, and Lacy Cooper, applied for the position.

[43] Defense attorneys acting for Ms. Nubia Rodriguez allege that Ms Mitchell had contributed to prosecutorial misconduct committed by Maricopa County prosecutors in an attempt to get their client convicted of negligent homicide in the death of Phoenix police officer Paul Rutherford.