JAMES WOODCOCK/AP U.S. District Judge Richard F. Cebull of Montana is under fire for sending a racially charged email about President Barack Obama. Cebull said the message reflected his political views, but denied he’s a racist. Read more: http://www.nydailynews.com/news/politics/federal-judge-montana-emails-racist-joke-obama-article-1.1031703#ixzz2PQ4RE7gZ U.S. District Judge Richard F. Cebull (James Woodcock/Associated Press)

A federal judge who forwarded an e-mail featuring a racist joke about President Obama's mother has retired, effective May 3.

In March 2012, U.S. District Judge Richard F. Cebull of Montana admitted to forwarding the e-mail, which found its way to the Great Falls Tribune.

After the Tribune's report, Cebull acknowledged that the message was racist and apologized. He said his only intent was to criticize Obama's politics, not his race. Last fall,  Cebull stepped down as chief judge and took on a reduced caseload.

The U.S. 9th Circuit Court of Appeals opened a judicial misconduct investigation at the behest of both the liberal group Common Cause and Cebull himself. An order and memorandum produced as a result of that investigation in mid-March are confidential.

Cebull's retirement was announced in a statement from Judge Alex Kozinski of the 9th circuit.

The judge was nominated to the district bench by President George W. Bush in 2001 and served as chief judge from 2008. Previously, he was a U.S. magistrate judge for the District of Montana from 1998 to 2001.