John Horn, the former U.S. attorney for the Northern District of Georgia, has returned to King & Spalding as a partner in the special matters practice, as the firm calls its white-collar group.

Horn became the U.S. attorney in Atlanta in 2015, when his former boss, Sally Yates, became the deputy U.S. attorney for the Obama administration. He was succeeded last October by BJay Pak, the Trump administration appointee.

After a few months' hiatus to catch up with his three teenage kids, Horn, 49, said he rejoined King & Spalding on Monday for “the opportunities and the people.”

“They have a world-class white-collar platform, and Phyllis Sumner [the firm's chief privacy officer] has created this fantastic cyber and data-privacy practice,” Horn said. “That, combined with being able to practice with many friends, I think will make the day-to-day practice truly enjoyable.”

Horn is the fifth federal prosecutor that King & Spalding has recruited for its special matters practice in the past year. The group, with more than 100 lawyers firmwide, is one of its marquee practices.

He's also the fifth former U.S. attorney now at the firm, which last year in Chicago landed Zach Fardon, the ex-U.S. attorney for the Northern District of Illinois. The other three are: Paul Murphy and Jim Vines in Atlanta and John Richter in Washington.

King & Spalding has also lost several lawyers to the Trump administration, most notably the former head of its white-collar practice, Chris Wray, who joined the Justice Department as FBI director in August, then in January tapped another King & Spalding special matters partner, Zachary Harmon, as his chief of staff.

The head of King & Spalding's special matters and government investigations practice, Wick Sollers in Washington, in a statement called Horn a “superb lawyer and leader who is naturally collaborative.”

“John's prosecutorial experience and understanding of the process will provide our clients invaluable insights when enforcement agencies come calling,” Sollers added.

Horn spent 15 years at the U.S. Attorney's Office, joining from King & Spalding's special matters practice in 2002. He became deputy chief of the Narcotics & Organized Crime Drug Enforcement Task Force, then Appellate Division chief and first assistant U.S. attorney under Yates. As U.S. attorney, Horn started the first cybercrime and civil rights enforcement units for the Northern District of Georgia.

Horn acknowledged it's a big change to go from prosecution to defense, but said, “a lot of it is relational in terms of the relationships, trust and credibility that you develop in either setting. I feel like that credibility will translate on both sides.”

During his tenure, Horn prosecuted some high-profile cases against international drug cartels, including the 2016 conviction of a Mexican cartel leader, Edgar Valdez-Villareal, aka La Barbie, of the Beltran-Leyva cartel for cocaine trafficking and money-laundering. “It was notable because we got so high up in the leadership of the cartel, dismantling its leadership and hierarchy,” Horn said.

Horn also led the largest of the DOJ's Drug Market Intervention initiatives to dismantle a decades-old heroin and crack marketplace operating in Atlanta's English Avenue community.

“One of the things I'm most proud of about my tenure at the U.S. Attorney's Office was our community engagement,” he said, “whether increasing our visibility with companies that were experiencing a disturbing increase in cybersecurity activity or holding mock trial programs for kids so they could see they had a positive future.”

At King & Spalding, Horn said, he intends to stay involved in the community revitalization happening on the Westside. “I plan to keep working with a lot of my prior partners, including the Atlanta Police Department and the Urban League of Atlanta, to further my engagement for safer and healthier communities,” he said.