Gonzalez served as president of the Board of Supervisors and narrowly lost the 2003 race for mayor to Gavin Newsom.
He is now returning to the public defender's office, where he worked as a deputy public defender from 1991 until taking office as supervisor in 2001.
Public Defender Jeff Adachi announced at a staff meeting this morning that Gonzalez would be taking over as chief attorney, effective immediately, spokeswoman Tamara Barak Aparton said.
"We wanted a top trial lawyer who understands our work, has a commitment to our clients and a dedication to preserving the resources that allow our office to function," Adachi said in a statement.
He said Gonzalez's experience in the courtroom and at City Hall makes him an excellent fit for the chief attorney position, which involves overseeing and managing all internal operations of the public defender's office, and also participating in budget planning and negotiations.
The chief attorney is essentially second-in-command to the public defender, Barak Aparton said.
Gonzalez is replacing former Chief Attorney Teresa Caffese, who left Dec. 31 for private practice.
Since 2005, Gonzalez has worked as a partner at the law firm of Gonzalez and Leigh, where he handled both civil and criminal matters.