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William Sinclair

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Phone: (410) 385-9116
Fax: (410) 547-2432

201 N Charles St 26th Floor
Baltimore, Maryland 21201

Secretary / Assistant
Nicole Wilson

J.D., University of Virginia School of Law, 2002

B.A., University of California at San Diego, 1999
Magna Cum Laude

Jurisdictions District of Columbia
State of California
State of Georgia
State of Maryland
U.S. District Court: Eastern, Northern and Southern Districts of California; District of Columbia; Northern District of Georgia; District of Maryland
U.S. Courts of Appeal for the Fourth, Ninth and Eleventh Circuits

Bill Sinclair is the partner-in-charge of the Firm’s Business Litigation Group, where he practices in the areas of white-collar criminal defense and complex civil litigation, including toxic torts, real estate and business litigation, and personal injury, and Trusts and Estates Group, where he handles all the Firm’s trusts and estates related litigation.  He also handles select transactional matters for clients.

Professional History
Mr. Sinclair’s practice covers a wide-range of civil and criminal matters in Federal and State courts and before administrative tribunals throughout the country.  He has defended corporations, individuals, and public agencies and utilities in toxic tort, environmental, and product liability cases; commercial matters; land use, construction and other real estate disputes; and environmental, health care, and securities enforcement proceedings and investigations as well as other complex crimes.  Mr. Sinclair has also served as plaintiffs’ counsel in contract, commercial and land use disputes, select personal injury matters, and civil rights cases.

Class actions constitute a significant part of Mr. Sinclair’s practice.  He was co-lead plaintiff’s counsel in a Federal class action against a local municipality that resulted in significant monetary and injunctive relief for his clients and was co-lead defense counsel in a State putative class action product liability suit against a local utility that resulted in a significant defense win.  He currently serves as co-lead plaintiffs’ counsel in the National Hockey League Concussion Litigation and as co-lead defense counsel in a series of putative and certified class actions in Maryland involving RESPA and other real estate matters.   

Mr. Sinclair has served as an adjunct professor at the University of Maryland School of Law since 2009.  Prior to moving to Baltimore and joining STSW, Mr. Sinclair was an associate at Alston + Bird LLP in Atlanta and Beveridge & Diamond, P.C. in Washington, DC.

Mr. Sinclair graduated from the University of Virginia School of Law, where he was a member of Omicron Delta Kappa, Editor-in-Chief of the Virginia Environmental Law Journal, and Head Commissioner of the North Grounds Softball League, and the University of California at San Diego, where he was Phi Beta Kappa and received Highest Honors in History.  While in college, Mr. Sinclair was captain of the Men’s Division I Varsity Volleyball team and the recipient of several academic and athletic awards.

Representative Matters and Engagements
•    Obtained dismissal of RESPA count against title company which was upheld before the Maryland Court of Special Appeals;
•    Successfully compelled arbitration of Federal complaint, essentially dismissing the case;
•    Obtained dismissal of State tort claims against individual physicians in business dispute;
•    Member of litigation team that obtained a $1.8 million dollar verdict in complex insurance case;
•    Successfully defended the issuance of a Clean Water Act permit necessary to the development of a new rail facility;
•    Obtained declaratory relief for a developer in a dispute with residents over use of a private beach;
•    Successfully defended a State agency decision to proceed with a new highway project;
•    Successfully defended a health care provider against Federal fraud and kickback charges.      
Government Service
  • 2003-04 Law Clerk, Hon. C. Christopher Hagy, U.S. District Court for the Northern District of Georgia

Who Rules the Roost? CWA Liability After Md. Ruling, Product Liability Law360, Portfolio Media Group (September 2010)

Status Check: Assessing Interior’s Implementation of the Energy Policy Act of 2005, Sustainable Development Law & Policy, Vol. VII, Issue 3 (Spring 2007)

Future of the “Feeney Amendment” After High Court’s Sentencing Rulings, Legal Backgrounder, 2005

Honors and Awards
Super Lawyers Badge

Maryland Super Lawyers, 2013-2018

Maryland Top 100, 2017 - 2018


Bar Association for Baltimore City

Baltimore County Bar Association

State Bar of California

The District of Columbia Bar

State Bar of Georgia

Maryland State Bar Association
Chair, Membership Committee
Fellow, Leadership Academy