John Horn, the U.S. attorney for the Northern District of Georgia since the 2015 departure his former boss, Sally Yates, is leaving the office where he spent 15 years as a prosecutor now that his successor and former colleague Byung J. “BJay” Pak, has been confirmed.

Horn told the Daily Report that he's notified staff he will leave as soon as Pak settles in. Horn has “no firm plans yet for the post-prosecutor world.”

Because Horn was not a political appointee, he retained the option to remain as a career prosecutor after Pak was sworn in. Horn, who served as first assistant U.S. attorney during Yates' tenure, was appointed acting U.S. attorney when Yates was confirmed as the Obama administration's deputy attorney general. He was named U.S. attorney in a court order issued by the Northern District of Georgia in December 2015.

The judicial order bypassed what is normally a presidential appointment that requires Senate confirmation. Under 28 U.S.C. §546, acting and interim appointments for U.S. attorney are made by the attorney general and have expiration dates. But, if an appointment expires, the local district court may temporarily appoint a U.S. attorney without Senate confirmation to serve until the vacancy is filled via a presidential nomination.

“Serving as U.S. Attorney has been my life's greatest privilege and honor,” Horn said in a written farewell. ”Each day, I have served alongside incredibly talented and dedicated men and women who epitomize our mission to seek justice on behalf of the citizens of this country.”

“It is impossible to convey the depth of my appreciation to the federal, state, and local law enforcement officers who served alongside us, as well as to the countless community leaders and residents who supported and partnered with us,” he continued. “Together, we have restored the rights of so many victims, brought those who have done harm to justice, and worked to improve the quality of life of our neighbors. To my colleagues, partners, and fellow citizens: a sincere thank you.”

Horn also conveyed his best wishes to Pak. The two served together as assistant U.S.attorneys before Pak left the office to return to private practice.

“BJay's skillful leadership and superb judgment will lead the office to even greater accomplishments, and safeguard the tradition of honor and integrity firmly established by those who served in this office before us,” Horn said.

Horn was an attorney at King & Spalding when he joined the U.S. Attorney's Office, which was headed by another former King & Spalding lawyer at the time: now U.S. District Judge William Duffey Jr.

Since former U.S. Attorney General Griffin Bell was at King & Spalding, the law firm has encouraged its younger lawyers—Yates and newly-minted FBI Director Christopher Wray among them—to serve stints as federal prosecutors.

Horn joined Yates as part of a team that prosecuted Olympic Park bomber Eric Robert Rudolph.

After he was confirmed, Pak told the Daily Report that he and Horn both joined the U.S. Attorney's Office in 2002. “We are friends,” he said, adding Horn “has pledged his full support” and been “more than gracious” about the transition. “John is a great public servant,” Pak added. “Whatever he does, he does with a servant's heart.”