Appointments strengthen the Firm’s sophisticated bench of lawyers in Boston, Chicago,
Philadelphia, and Washington, D.C.
New York, NY – Pierson Ferdinand LLP (“PierFerd” or the “Firm”), one of the world’s fastest-growing law firms, welcomes five (5) new Partners in July 2026 across its Intellectual Property and Litigation Departments.
The appointments reflect PierFerd’s sustained investment into its core practice areas and its expansive geographic reach. The Firm’s flexible, Partner-led, and tech-enabled model continues to attract experienced attorneys from leading law firms across the United States and globally.
Richard (Rick) E. Darst joins in Boston, Massachusetts as a Partner in the Litigation Department, focusing his practice on representations and warranties insurance coverage investigations, insurance litigation, and complex commercial disputes on behalf of insurers, managing general agents, and corporate clients. He also has significant experience litigating large and complex commercial claims in both state and federal courts nationwide, including post-M&A, breach of contract, fraud, fiduciary duty, and private equity-related disputes.
Prior to joining PierFerd, Rick practiced at Brown Rudnick LLP. He earned a B.A. from Providence College and a J.D. from the Northeastern University School of Law. Rick is admitted to practice in Massachusetts and Rhode Island.
P. Kai Knight joins in Washington, D.C. as a Partner in the Litigation Department, bringing nearly a decade of experience focusing on privacy and data security, helping clients comply with both domestic and global data protection laws. He assists businesses with swift responses to cybersecurity threats, including ransomware attacks and business email compromises, and counsels clients navigating federal and state investigations that follow such incidents.
Prior to joining PierFerd, Kai was a Counsel at Lowenstein Sandler LLP. Previously, he practiced at Alston & Bird LLP, Mayer Brown LLP, and Sidley Austin LLP. Kai earned a B.I.S., summa cum l aud e, from Arizona State University and a J.D. from Georgetown University Law Center. Kai is admitted to practice in the District of Columbia.
Matthew (Matt) C. DiMaio joins in Philadelphia, Pennsylvania as a Junior Partner in the Litigation Department, bringing extensive experience focusing on complex litigation matters as well as business and real estate transactions. He also has experience in music, entertainment, and intellectual property law, specifically involving copyright and trademarks.
Prior to joining PierFerd, Matt practiced at Montgomery McCracken Walker & Rhoads LLP. Previously, he practiced at Astor Weiss Kaplan & Mandel, LLP and Obermayer Rebmann Maxwell & Hippel LLP. Matt earned a B.A., cum l aud e, from The University of Scranton and a J.D. from the Villanova University Charles Widger School of Law. He is admitted to practice in New York and Pennsylvania.
Mariah Leffingwell joins in Washington, D.C. as a Junior Partner in the Litigation Department, bringing significant experience focusing on data privacy, cybersecurity, and admiralty andmaritime matters. She guides clients through data breach incident response, minimizing cyber risks, and complying with a broad range of cybersecurity and data protection laws and regulations. These include the California Consumer Privacy Act (CCPA), the Health Insurance Portability and Accountability Act (HIPAA), and the General Data Protection Regulation (GDPR).
Prior to joining PierFerd, Mariah practiced at Clark Hill PLC. Previously, she practiced at K&L Gates LLP. Mariah earned a B.A. from St. Mary’s College of Maryland, a J.D. from Roger Williams University School of Law, and an LL.M. from Tulane University School of Law. She is admitted to practice in the District of Columbia and Maryland.
Sofia Quezada Hastings joins in Chicago, Illinois as a Junior Partner in the Intellectual Property Department, bringing extensive experience focusing on intellectual property litigation, prosecution, and counseling. She advises clients on the protection and enforcement of their trademarks and copyrights.
Prior to joining PierFerd, Sofia practiced at Aronberg Goldgehn Davis & Garmisa. Previously, she practiced at Sullivan & Carter LLP. She earned a B.A. from The University of Texas at Dallas and a J.D. from DePaul University College of Law. She is admitted to practice in Illinois.
A total of five (5) Partners joined PierFerd in July, reflecting the Firm’s continued momentum and its status as a destination for accomplished, experienced lawyers.
About PierFerd
Pierson Ferdinand LLP is an international law firm serving clients globally from 25+ markets. Its 290+ Partners practice in 90+ areas of law, including corporate, M&A, securities, employment and executive compensation, intellectual property, litigation, private clients & estates, and tax. Its Partners have a reputation for excellence and have significant experience practicing in preeminent law firms, corporate legal departments, and government.[1]
1 In London, the firm operates as Pierson Ferdinand UK LLP, a limited liability partnership registered in England & Wales with registered number OC449880. It is authorized and regulated by the Solicitors Regulation Authority with registered number 8006801.
Pierson Ferdinand UK is connected with its affiliate in the United States, Pierson Ferdinand LLP, although they are two separate legal entities.
The word “partner” denotes a member of Pierson Ferdinand UK or an employee or consultant with equivalent standing and qualifications.
