Katherine Celeste Speegle A veteran antitrust litigator at the U.S. Department of Justice left the federal government to join Duane Morris LLP as a partner, the firm has announced.

Katherine Celeste Speegle has joined the firm's trial practice group, supporting the firm's New York and Washington, D.C., offices, Duane Morris said Monday. Most recently, Speegle was assistant chief in the transportation, energy and agriculture section at the Antitrust Division of the DOJ.

Speegle told Law360 Pulse in a Wednesday interview that after six years as assistant chief at the DOJ, she felt like she had learned the ropes, had a great run and was ready for a new challenge. She was drawn to the firm by its antitrust practice and its culture, which a friend of hers in the trial practice vouched for.

"The antitrust practice is expanding, and they have a lot of interesting matters that I've actually started working on already. And the energy there, it's just off the charts," Speegle said. "It's an exciting time to be there. I wanted to be joining a place that felt dynamic, where I felt like I would have the ability to really contribute."

At Duane Morris, Speegle said she plans to focus her work on antitrust, doing a mix of litigation and deal work, mirroring her experience at the DOJ. She added that the firm has industry groups that focus on certain areas, including energy, and she expects that will be a great place for her to use her skills.

The firm's chairman and CEO Matthew A. Taylor said in the statement that the firm is pleased to add accomplished, talented new partners to the litigation practice, and Speegle's addition in New York City continues the firm's recruiting momentum in 2026.

"Our client work in antitrust and competition matters is well-known, and Katie's first-hand insight into how the Department of Justice evaluates competitive effects, remedies and litigation posture is experience that will enhance Duane Morris's ability to counsel clients facing heightened antitrust scrutiny in an increasingly complex policy and enforcement environment," Taylor said.

A graduate of Georgetown University Law Center, Speegle spent the last 16 years at the DOJ. She said she spent her entire career in the transportation, energy and agriculture section.

Speegle said she was a trial attorney for about the first 10 years, then spent the last six years as an assistant chief. She added that she also worked outside the section on some other commodities as well.

In 2018, Speegle completed a stint as a special assistant U.S. attorney at the U.S. Attorney's Office for the Eastern District of Virginia.

When asked if there were notable cases that gave her experience she'd take with her in her new role, Speegle pointed to her work on the suit against JetBlue and Spirit Airlines to enjoin their merger and the suit against the American Airlines and JetBlue joint venture.

The American Airlines and JetBlue joint venture was permanently grounded in 2023, while the JetBlue and Spirit merger was blocked in 2024.

"Katie's depth of experience inside the Antitrust Division gives her a unique perspective on litigation, enforcement priorities and decision-making at the agency," Sean McConnell, chair of Duane Morris' antitrust division, said in the statement. "Her addition strengthens our ability to guide clients through government investigations, merger review and complex antitrust litigation. She will be immediately helpful to our healthcare, life sciences and energy industry teams, where we are currently representing clients in nationally significant matters relating to conduct challenges and investigations."