D. Sean "Sean" McMahon

For nearly 30 years, he has dedicated his energy to representing entrepreneurs and investors in venture-backed and pre-venture businesses. He works with companies from inception through exits that typically involve complex merger and acquisition transactions. David’s clients range from local start-up companies to multinational businesses, investors and entrepreneurs around the world that are active buying, selling and financing companies. Building on his core expertise in the technology...

Ashley leads Sullivan's Real Estate Group and is a member of the firm's Management Committee. Ashley’s practice focuses on all aspects of real estate development, including commercial development, complex debt and equity structures, ground leases, loan workouts and restructures, acquisitions/dispositions, and leasing transactions. Ashley represents a broad spectrum of clients, from international to family office developers, institutional investors to public and private companies, and go...

Karen F. Turk is a top attorney recognized by Best Lawyers in the practice area(s) of Tax Law. Karen F., who practices law in Boston, Massachusetts, has been recognized since 2023. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Karen F. is held by other top lawyers in the same geographic and legal practice area.

John’s entire legal career has been devoted to U.S. immigration and nationality law. His practice covers all facets of employment- based immigration, as well as family immigration and naturalization. He has in-depth experience providing strategic advice and counsel to both small entrepreneurial businesses and to multinational corporations. An AV-rated immigration attorney for more than a decade, John is also nationally recognized for his expertise in representing distinguished professor...

Mark Fleming is co-chair of WilmerHale's Appellate and Supreme Court Litigation Practice. He is an accomplished and well-regarded litigator who has appeared in more than 300 appellate cases and personally presented oral argument in 77 of them, including eight oral arguments before the Supreme Court of the United States. He has also argued before the Supreme Judicial Court of Massachusetts, the Massachusetts Appeals Court, and the First, Second, Third, Eighth, Ninth, Tenth, Eleventh, Federal, ...

Gina A. Fonte is a top attorney recognized by Best Lawyers in the practice area(s) of Construction Law. Gina A., who practices law in Boston, Massachusetts, has been recognized since 2025. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Gina A. is held by other top lawyers in the same geographic and legal practice area.

Jonathan A. ("Jon") Karon is the founder of the Boston firm Karon Law, LLC. He has a national practice representing the catastrophically injured including cases involving traumatic brain injuries, amusement ride accidents, motor vehicle crashes and dangerous products. He is a past President of the Massachusetts Academy of Trial Attorneys and is currently an Officer of the Traumatic Brain Injury Litigation Group of the American Association for Justice (AAJ). His noteworthy cases include succes...

Philip S. Lapatin is a member of the Real Estate Department and concentrates his practice in the representation of landlords and tenants in commercial leasing transactions. In particular, Mr. Lapatin is counsel to owners of several downtown Boston office buildings. Mr. Lapatin has been providing legal advice as general counsel to the Greater Boston Real Estate Board and its divisions since 1973, including suits in which rent control ordinances and condominium conversion restrictions were inva...

Erik J. Winton is a top attorney recognized by Best Lawyers in the practice area(s) of Employment Law - Management and Litigation - Labor and Employment. Erik J., who practices law in Boston, Massachusetts, has been recognized since 2019. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Erik J. is held by other top lawyers in the same geographic and legal practice area.

William M. Shields is a top attorney recognized by Best Lawyers in the practice area(s) of Corporate Law, Leveraged Buyouts and Private Equity Law and Mergers and Acquisitions Law. William M., who practices law in Boston, Massachusetts, has been recognized since 2021. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which William M. is held by other top lawyers in the same geographic and legal practice area.