

Glenn Fine, a top internal watchdog at the U.S. Justice Department for a decade, has submitted letters of resignation, saying he wants to "pursue new professional challenges."

Fine, 54 and pictured above, will step down as DOJ's inspector general effective Jan. 28, according to copies of letters addressed to President Barack Obama and Attorney General Eric Holder Jr. The letters are dated today.

His tenure has been marked recently by high-profile investigations into allegations of misconduct by former Attorney General Alberto Gonzales and his staff. Together with DOJ’s other internal watchdog, the Office of Professional Responsibility, Fine’s staff dug into the firings of U.S. attorneys, the shifts in the department’s Civil Rights Division and other topics.

Even aside from those scandals, the position of DOJ inspector general is highly sensitive. The office oversees audits and investigations of potential waste, fraud and abuse amid the billions of dollars the department spends each year.

“The Department, the Congress, and the public have received great value from the work of the OIG over the years, and it has been the high point of my professional career to work with so many dedicated public servants in the OIG,” Fine wrote to Holder (PDF). “I will always be grateful for the opportunity to have served as the Inspector General at the Department of Justice.”

Obama is expected to nominate a successor, who will need Senate confirmation. No acting inspector general has been named. Cynthia Schnedar is Fine’s deputy, and he praised her as a “strong” deputy in his letter to Holder.