According to this story from the Arizona Capitol Times, written by Caitlin Coakley Beckner (subscription required), Rep. Richard Miranda (D-Tolleson) has resigned from the Arizona House of Representatives, effective Monday.
In his letter, he cited health and family concerns as the reason for his resignation.
In short order, the Democratic PCs in LD13 will gather to select three nominees, whose names will be forwarded to the Maricopa County Board of Supervisors. They will then select the person who will serve the remainder of Miranda's term.
While it isn't an official rule, traditionally, the supervisor in whose district the affected legislative district is located usually has the final say on the selection. The other supes generally rubber-stamp that decision.
LD13 is located in the supervisorial district of Mary Rose Wilcox, the lone Democrat on the Maricopa County Board of Supervisors. While there could be some game playing by the Rs on the MCBOS, there probably won't be - they have nothing to gain from it. Under state law, they must select a D to fill a vacancy in the lege left by a D, and the Rs in the lege will retain a supermajority in the lege regardless of who is chosen to fill the LD13 seat.
In addition, after their protracted recent battles with Joe Arpaio and Andrew Thomas (which, to be clear, were mostly the fault of Arpaio and Thomas), the supes may not be itching for another unnecessary pissing match.
I've got a call out to the chair of the LD13 Democrats for info about the schedule of events to select candidates to replace Miranda, but she hasn't returned that call as of this writing.
More updates when they become available...