D. Kyle Sampson, former chief of staff to Attorney General Alberto R. Gonzales, is set to testify before a Senate committee on Thursday.

Mr. Sampson resigned earlier this month and is testifying voluntarily.

The Senate Judiciary Committee hopes to learn more about what happened at the Justice Department leading up to the firing of eight federal prosecutors last year.

Mr. Sampson's former boss, Mr. Gonzales, has said he knew little about the firings, and indicated that Mr. Sampson worked unilaterally within Justice, without notifying superiors of important details.

Mr. Gonzales has said this lack of communication caused inaccurate testimony to Congress by Justice officials.

Mr. Sampson will give his side of the story on Thursday.

-- Jon Ward, White House correspondent, The Washington Times