On matters of national security, Attorney General Eric Holder leaving with a mixed record

Audience members applaud Attorney General Eric Holder, right, and President Barack Obama during an announcement in the State Dining Room of the White House to announce Holder is resigning, on Thursday, Sept. 25, 2014, in Washington. Holder, who served as the public face of the Obama administration's legal fight against terrorism and weighed in on issues of racial fairness, is resigning after six years on the job. He is the first black U.S. attorney general. (AP Photo/Evan Vucci) (The Associated Press)

Outgoing Attorney General Eric Holder speaks at the Voting Rights Brain Trust event, Friday, Sept. 26, 2014, during the 2014 Congressional Black Caucus Annual Legislative Conference in Washington. On Thursday, Holder announced he would be stepping down as attorney general. (AP Photo/Molly Riley) (The Associated Press)

President Barack Obama, right, looks on as Attorney General Eric Holder speaks in the State Dining Room of the White House, on Thursday, Sept. 25, 2014, in Washington. Holder, who served as the public face of the Obama administration's legal fight against terrorism and weighed in on issues of racial fairness, is resigning after six years on the job. He is the first black U.S. attorney general. (AP Photo/Evan Vucci) (The Associated Press)

Attorney General Eric Holder was just months into the job when he announced plans to prosecute the mastermind of the Sept. 11 attacks in a New York courtroom, rather than through the Guantanamo Bay military commission process.

But the idea ran into political opposition and public safety concerns.

The Obama administration's eventual decision to walk away from it was a defeat for Holder and a reminder of the complex legal fight against terrorism.

Holder took office determined to turn the page from Bush administration policies that authorized harsh interrogation techniques against suspected terrorists.

But he will leave with a mixed record of national security decisions that have drawn their own scrutiny and disappointed those who felt he didn't go far enough to distance the Justice Department from past practices.