William M. McSwain


  • William M. McSwain
  • Phone: +1 215 979 1166

    Import to Address Book

  • Duane Morris LLP
    30 South 17th Street
    Philadelphia, PA 19103-4196

William M. (Bill) McSwain is co-chair of the firm's White-Collar Criminal Defense, Corporate Investigations and Regulatory Compliance Group. He practices in the area of litigation with a focus on white-collar criminal matters, internal investigations and complex business litigation. Bill is the immediate past U.S. Attorney for the Eastern District of Pennsylvania (EDPA), which is one of the nation’s most populous districts, with nearly six million people residing within Philadelphia and its eight surrounding counties. As U.S. Attorney, he served as the chief federal law enforcement officer in the EDPA, responsible for all federal criminal prosecutions, investigations and civil litigation involving the United States. He supervised a staff of approximately 300, including more than 140 Assistant U.S. Attorneys, at offices in Philadelphia and Allentown, PA.

Most importantly, Bill is a fighter who knows how to win. For example, as U.S. Attorney, he personally served as lead counsel in United States v Safehouse, in which he challenged Philadelphia’s plan to be the first city in the country to open supervised heroin injection sites. He argued and won the case in the U.S. Court of Appeals for the Third Circuit, which ruled that such sites would violate the federal Controlled Substances Act.

A former U.S. Marine Corps infantry officer and scout/sniper platoon commander, Bill brings an aggressive and creative approach to private practice, representing clients involved in government investigations and high stakes litigation. In particular, he enjoys taking on the challenge of winning seemingly “impossible” cases. He has lived that mindset from the very outset of his legal career.

For example, prior to his service as U.S. Attorney, Bill took on the case of an Iranian immigrant, Ken Hamidi, who was locked in a battle with Intel over emails that Mr. Hamidi has sent to Intel employees. After Mr. Hamidi had lost his case in the trial and intermediate appellate courts with other counsel, Bill took over and argued the case in front of the Supreme Court of California. In Intel Corp. v. Hamidi, 30 Cal.4th 1342 (2003), he won a 4-3 decision that established the legal rules for trespass liability on the Internet, one of the most significant cyberlaw rulings in the United States. Soon thereafter, Bill represented Chester County, Pennsylvania in its dispute regarding the attempted removal of an historic Ten Commandments plaque hanging on the façade of the County Courthouse. After the County lost at trial with other counsel, Bill stepped in and argued the case in front of the U.S. Court of Appeals for the Third Circuit. In Chester County, PA v. Freethought Society, et al., 334 F.3d 247 (3d Cir. 2003), he won a 3-0 decision that preserved the plaque, which is hanging on the Courthouse to this day. In one of his most challenging assignments, Bill began representing the Boy Scouts in 2008 in its dispute with the City of Philadelphia. Facing eviction from its historic headquarters building, the Scouts sued the City, alleging a violation of their First Amendment rights. In Cradle of Liberty Council, Boy Scouts of America v. City of Philadelphia, No. 2:08-cv-02429-RB (E.D. Pa.), Bill won a nationally publicized, three-week jury trial, and even secured a court ruling that the City had to pay the Scouts’ attorney’s fees.

Bill understands that, in a very real sense, anybody or any organization squaring off against the government – especially against the federal government – is an underdog. Bill has a long record of success advocating for clients in those situations. For example, in United States v. Bruno, No. 2:13-cr-00039-LS-6 (E.D. Pa.), he represented a Pennsylvania judge against federal conspiracy, wire fraud and mail fraud charges and won a full acquittal after a two-month jury trial. In United States. v. Brown, No. 2:12-cr-00367-RBS-1 (E.D. Pa.), Bill represented a nationally renowned charter school educator who faced a massive 67-count indictment alleging conspiracy, wire fraud, obstruction of justice and witness tampering. After a two-month trial, the jury acquitted Bill’s client on several counts and deadlocked on the others. The government eventually withdrew all of the deadlocked charges.

His record in the courtroom notwithstanding, Bill is also a thoughtful, intellectually curious strategist who has resolved numerous contentious matters out of court on terms his clients found favorable. He is a graduate of Yale University (B.A., cum laude, 1991) and the Harvard Law School (J.D., 2000), where he was an editor of the Harvard Law Review, won the Ames Moot Court Competition and received the George Leisure Award as the Best Oralist in the Ames Competition. He is an adjunct lecturer in law at the University of Pennsylvania Law School. He began his legal career by clerking for the Hon. Marjorie O. Rendell, U.S. Circuit Judge of the U.S. Court of Appeals for the Third Circuit.


  • Pennsylvania
  • Supreme Court of the United States
  • U.S. Court of Appeals for the Third Circuit
  • U.S. District Court for the Eastern District of Pennsylvania
  • U.S. District Court for the Middle District of Pennsylvania
  • U.S. District Court for the Western District of Pennsylvania


  • Harvard Law School, J.D., 2000
    - Editor, Harvard Law Review
  • Yale University, B.A., cum laude, 1991


  • Duane Morris LLP
    - Partner, 2021-present
  • U.S. Attorney’s Office, Eastern District of Pennsylvania
    - U.S. Attorney, 2018-2021
    - Assistant U.S. Attorney, 2003-2006
  • Drinker Biddle & Reath LLP
    - Partner, 2009-2018
    - Associate, 2006-2009
  • Dechert LLP
    - Associate, 2001-2003
  • U.S. Court of Appeals for the Third Circuit
    - Law Clerk to the Hon. Marjorie O. Rendell, 2000-2001

Honors and Awards

  • Listed in Chambers USA: America's Leading Lawyers for Business, 2023 and 2024