About David Marshall Datz, P.C.

Our Firm

At David Marshall Datz, we combine decades of legal expertise with a deep commitment to community, inclusion, and personalized service. With welcoming offices in Boston’s South End, Provincetown, and Orleans, our boutique firm proudly serves a diverse range of clients across Massachusetts—from first-time homebuyers to seasoned real estate investors—offering thoughtful guidance in residential and commercial real estate law and estate planning.

Founded in 1999 by David Marshall Datz, our practice reflects the values of trust, respect, and authenticity. As a proudly LGBTQ+ owned firm, we’re more than legal advisors—we’re your neighbors, advocates, and partners in building a secure future. Whether you're buying your first condo, developing a commercial property, or creating a plan to protect your legacy, we’re here to make the process seamless, empowering, and genuinely human.

Our Team

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    David M. Datz, Esq.

    Founder and President

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    David is a skilled attorney specializing in real estate and estate planning representing owners, developers, buyers, and sellers in drafting and negotiating agreements for a wide range of properties, from condominiums and lofts to commercial spaces. With expertise in both residential and commercial transactions, David also manages property financing and oversees the firm’s commercial real estate leases.

    A native of Providence, Rhode Island, David holds a Bachelor’s degree in Business Administration (Marketing) from Bryant University and a Juris Doctor from New England Law in Boston. He has a strong background in condominium law, serving as counsel to numerous condominiums, advising on operations, document updates, refinancing, and vendor contracts. David is active in the Real Estate Bar Association and serves on its Conveyancing Leadership Council. He is also a volunteer mediator for the Bankruptcy Court Mediation Project and a respected real estate instructor in Massachusetts.

    In estate planning, David works with clients to create tailored plans focused on estate taxation, gifting, probate, and asset distribution. As a member of WealthCounsel™, he stays at the forefront of resources in the estate planning field.

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    Michael J. Clancy, Jr., Esq.

    Partner

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    As a Partner at the firm, Michael Clancy focuses on residential and commercial real estate transactions throughout Boston’s most desirable neighborhoods and the waterfront towns of Cape Cod. He advises buyers, sellers, lenders, and developers with a practical, client-first approach and deep experience in financing, title review, contract negotiation, and due diligence.

    Michael has built a reputation for his ability to navigate complex negotiations with clarity and efficiency—often finding common ground and delivering results that meet his clients’ goals. Prior to joining the firm, he served as an Associate Attorney at a boutique real estate law firm in Boston. Over the course of his career, he has successfully closed thousands of transactions. Michael is also a licensed Real Estate Broker in Massachusetts.

    He currently resides in Dorchester and can often be spotted walking through the South End with his mini long-haired dachshund, Biscuit. Outside of work, Michael enjoys traveling, staying active, spending time with family in Mattapoisett, and cheering on the Patriots. 

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    Ryan W. Cunningham, Esq.

    Associate Attorney

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    With nearly 15 years of experience in Massachusetts real estate law, Ryan W. Cunningham provides expert legal counsel to homebuyers, sellers, and homeowners refinancing their properties. Known for his precision, responsiveness, and deep understanding of local real estate practices, he ensures every transaction is handled with care and attention to detail.

    Ryan offers white glove service—delivering personalized guidance, clear communication, and zealous representation from offer to closing. His services include contract negotiation, title review and certification, closing representation, and asset protection strategies.

    Whether you're buying your first home or you’re refinancing a property, Ryan is committed to protecting your interests and making the process smooth, secure, and successful.

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    Jim Mauro

    Business and Office Manager

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    Jim handles much of the business side of the firm, such as accounts receivable, accounts payable, information technology, payroll, facilities management, and some HR. He also participates in the real estate closings in our Provincetown office, and you may also hear him answer the phones. 

    Jim attended Boston College, where he earned a degree in economics. Since then, he has had numerous positions in corporate information technology, most recently working as a senior security analyst under the Director of Worldwide IT Security at The Boston Consulting Group. Jim has been with the firm since 2010 and enjoys providing excellent customer service.

    Jim lives in Provincetown with his husband David and two dogs, Luna and Levi. He enjoys travel, keeping fit, and quiet nights being home with his family. You can reach out to him via email or see him on Facebook. 

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    Vered Doner

    Sr. Paralegal

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    Vered received her Paralegal’s Certificate in 2004, and has been with David Marshall Datz Law, P.C. since 2007.  With several years of experience working as a real estate paralegal, Vered handles the majority of the closings for the firm. She continues her education part-time to eventually reach her goal of becoming an attorney.

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    John F. Shea

    Title Paralegal

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    John has been a Title Paralegal with David Marshall Datz Law, P.C. since 2008.  John began his career as a Title Examiner for the law firm Withington Cross Park & Groden in 1983. Beginning in 1987, John was a title underwriter in both the residential and commercial real estate divisions of Fidelity National Title Insurance Company, Lawyers Title Insurance Company, and First American Title Insurance Company.

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    Frank Girvan

    Legal Assistant

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