Mark B. Langdon

Danielle Morris has 15 years of experience advising clients on all aspects of international arbitration. Her practice spans both private and public international law, with a focus on investor-State arbitration. She has worked on a range of commercial and investment arbitrations, both institutional and ad hoc, from the pre-dispute and notice of dispute stage through merits submissions and hearings through to set-aside and enforcement. She also assists clients with investment planning and advis...

Randall Rich is the partner-in-charge of the Washington, DC office. Throughout his over 40 years of experience, beginning in the Office of General Counsel of the Federal Energy Regulatory Commission (FERC) and continuing for more than 23 years at the DC office of a large Texas law firm, Randy always strives to form close personal bonds with clients as well as trusting relationships with both regulators and his colleagues in the energy bar. He gains an intimate understanding of the business an...

Christopher Mangin, Jr. is a top attorney recognized by Best Lawyers in the practice area(s) of Leveraged Buyouts and Private Equity Law and Mergers and Acquisitions Law. Christopher, who practices law in Washington, District of Columbia, has been recognized since 2023. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Christopher is held by other top lawyers in the same geographic and legal practice area.

Nancy P. Regelin uses her skills as a strategic thinker, communicator, and manager to implement the vision of land owners, developers, and creative consultants to create great places for us to live, work and play. One of her true strengths lies in the trust and relationships she builds with elected officials, staff, community leaders, professional consultants, and other attorneys that she can draw upon to creatively solve problems. In a recent assignment, Nancy was selected as outside local z...

Personal injury and medical malpractice victims, and those who have been injured by the federal government, turn to Karl Protil when they need a lawyer who has a 20 year record of winning such cases. Clients depend on Karl when the stakes are high, and when their situations call for a lawyer who is not afraid to take chances when it comes to bringing the much needed emotional and financial closure they deserve. Victims benefit from his unique technical skill-set which includes both deep knowl...

Matt Alegi solves problems. A deal lawyer with significant experience in dispute resolution and regulatory compliance, clients hire him because his practical, results-driven approach gets things done. While his legal practice spans a wide range of real estate and finance-related areas, Matt primarily concentrates on representing buyers, sellers and lenders in the acquisition, sale and financing of real estate. His practice also involves advising lenders and borrowers regarding problem loans, ...

Alexander H. Xanttopoulos is a principal attorney with Roop, Xanttopoulos, Babounakis. He joined the predecessor firm in Fall 2010, to focus primarily on family law. He works in cases involving divorce, child custody, support, visitation and equitable distribution. Prior to joining Roop Law, Alex worked for several years for Greenspun, Shapiro, Davis and Leary P.C. as an associate practicing in the areas of domestic relations, traffic, criminal defense and civil litigation. He also has experi...

Sean Howley brings first-hand construction industry experience to his legal practice, having managed and worked on multi-million dollar public works projects in New York City and the surrounding area. After earning a Bachelor of Science in Civil Engineering from the University of Notre Dame, he worked as a Project Engineer and Project Manager for a heavy construction contractor. He later earned his Juris Doctor from St. John’s University School of Law and has since devoted his practice ...

Maureen is an experienced litigator who co-chairs the firm’s Litigation Practice Group and Class Action Practice Group. Maureen devotes a very substantial amount of her practice to wage and hour issues, including preventive consultation, internal audits, government investigations, and defense of wage and hour litigation, almost all of which include class or collective action claims. Maureen's wage and hour litigation experience includes cases involving state and federal minimum wage and...

Mr. Colten was born in New York City and has been a long-time resident of Virginia. After serving as Assistant Commonwealth's Attorney in Fairfax County for two years, Mr. Colten entered private practice in Northern Virginia. He was a founding member and principal of Surovell, Jackson, Colten & Dugan, P.C. and its predecessor and successor firms, prior to forming Colten | Watson | Vincent Law Group P.C. In 1965, Mr. Colten received his B.S. with a major in sociology from American Universi...