The Arizona Daily Star reports Judge pro tem Jose H. Robles tendered his resignation Friday. It was effective immediately.
Court spokeswoman Anne-Marie Braswell says the reason for Robles’ decision wasn’t known Friday
A three-day trial was scheduled to begin in his courtroom Tuesday.
Robles had been a Pima County judge since September 2009. His last case was the trial of 16-year-old Vicente Valles. He was charged with committing a brutal home invasion in April 2010.
Robles declared a mistrial Thursday after jurors were unable to reach a unanimous decision.