SAN FRANCISCO — Superior Court Judge Patrick Mahoney is stepping down from the bench and plans to launch a career as a mediator.

His departure, effective Jan. 18, will end a nearly 13-year judgeship at the court. Mahoney, who turns 70 this month, was appointed by Governor Gray Davis in 2000. He is a long-time member of the court’s Executive Committee and has served as supervisor of the Unified Family Court since 2010.