David M. Costigan

David M. Costigan, a member of Dechert's antitrust and competition group, is an experienced antitrust litigator and appellate advocate who represents clients in high-stakes antitrust and complex commercial disputes in federal courts across the United States. Mr. Costigan represents clients across a range of industries, including life sciences, technology, media, and manufacturing. His practice includes a particular focus on the intersection of antitrust and intellectual property law—including matters involving alleged reverse payment settlements and Walker Process fraud—and on the evolving antitrust issues confronting technology companies.

Mr. Costigan's pre-trial and trial experience spans all phases of complex antitrust litigation. In addition to trying cases before both judges and juries, he has drafted a broad range of dispositive motions—including motions to dismiss, oppositions to class certification, and motions for summary judgment—managed extensive fact and expert discovery, taken depositions, and prepared witnesses to testify.

Mr. Costigan also maintains an active appellate practice. He has authored merits briefs and amicus curiae briefs in cases before multiple federal Courts of Appeals and the United States Supreme Court. Recently, he successfully argued a Section 1983 civil rights appeal before the U.S. Court of Appeals for the Third Circuit, persuading the court to overturn a jury verdict.

Prior to joining Dechert, Mr. Costigan clerked for the Honorable Sandra L. Lynch of the U.S. Court of Appeals for the First Circuit.