Ann Marie Duffy

Ann Marie Duffy is an accomplished trial lawyer who has broad experience in the defense of complex civil litigation. With over 20 years of experience, she has represented companies in some of their most significant cases on a variety of claims, including commercial disputes, construction claims, products liability, environmental tort, fraud, and intellectual property claims. In one of the largest cases she has tried, Ann Marie served as second chair in a patent infringement trial in the United States District Court for the District of Delaware in a case where total damages exceeded $2 billion.

In addition to her trial experience, Ann Marie has briefed and argued appeals to the United States Court of Appeals for the District of Columbia Circuit, the United States Court of Appeals for the Tenth Circuit, and the State of New York Supreme Court, Appellate Division Third Judicial Department.

Currently, Ann Marie is lead counsel for a PFAS manufacturer defending against claims of negligence and personal injury in several states. She is also lead counsel for a producer of PTFE and silicone coated fabrics, tapes, and belts, defending against claims of negligence, trespass, and nuisance for its use and handling of materials containing trace amounts of PFOA. Ann Marie is a trial team partner in a major natural resource damages case involving claims of negligence and ecological harm in which the State is seeking hundreds of millions of dollars in economic compensation and primary restoration. She is also a trial team partner for a major engineering, procurement, and construction (EPC) contractor against alleged breach of contract, professional negligence, and fraud claims arising from the design, engineering, and construction of a nearly $1 billion agrochemical plant in Arkansas Circuit Court.