Nevada State Athletic Commission (NSAC) executive director Keith Kizer submitted his resignation Friday, stepping down from the role he has filled since 2006.
Kizer's resignation takes effect January 27, after which he will return to work within the Attorney General's office.
"It's time to move on," Kizer said in a statement, via the Las Vegas Review-Journal. "It's time to go back to being an attorney."
According to NSAC chairman Francisco Aguilar, Kizer's decision to step down was not forced, but one of his own accord. A search for Kizer's replacement is already underway.
"The board is grateful to Keith for his nearly eight years of dedicated service, which included the commission's strongest years with regard to health and safety and fiscal soundness," Aguilar said in a statement. "My fellow commissioners and I wish Keith all the best in his new role."
Kizer's tenure as NSAC executive director began in 2006, when he replaced now-UFC Vice President of Regulatory Affairs Marc Ranter. Over the course of his eight years of service, Kizer oversaw the sport of mixed marital arts during a time of explosive growth, presiding over nine of the 10 largest mixed martial arts gates in Nevada state history, along with four of the 10 largest boxing gates.
Kizer directed the push for increased drug testing within the state of Nevada, including more stringent pre- and post-fight drug tests for athletes competing in both mixed martial arts and boxing, as well as out-of-competition drug testing.
Within the realm of mixed martial arts specifically, Kizer infamously declared in 2013 that UFC middleweight contender Vitor Belfort would not be able to receive an exemption for testosterone replacement therapy in Nevada due to a past history with steroid abuse.
Nonetheless Kizer also became a source of controversy throughout his reign atop the NSAC, barring pioneering MMA referee John McCarthy from working within the state of Nevada and often drawing the ire of UFC President Dana White.
Within recent years, Kizer faced mounting criticism for the state of judging and refereeing within Nevada.
Most notoriously, Kizer appointed judge C.J. Ross to oversee last year's Floyd Mayweather vs. Canelo Alvarez mega-fight, despite the fact that Ross was one of two judges who awarded Timothy Bradley an indefensible split decision victory over Manny Pacquiao in 2012. Mayweather went on to dominate Alvarez, yet Ross bafflingly scored the fight a draw, awarding Mayweather a majority decision win.