Sandra MacGregor O’Brien


Sandra MacGregor O’Brien has been a practicing attorney for more than 35 years and is the lead attorney for the Probate and Trust Administration department of Casey & Lundregan.  Attorney O’Brien has considerable experience with all aspects of probate and trust administration from initial client interview through closing of the estate.

Prior to joining Casey & Lundregan, Attorney O’Brien was Assistant General Counsel to the American Patriot Group of companies including American Mutual Liability Insurance Company and served on the Board of Directors of American Patriot Group. Prior to that she was Assistant General Counsel with Sentry Insurance in Concord MA.  She began her legal career with a Boston firm specializing in medical malpractice.

Attorney O’Brien earned her JD degree from Western New England University School of Law and her BA from Smith College where she majored in Political Science. 
She resides in Lynn, MA with her husband, John O’Brien, the Register of Deeds for Essex South District, daughter Ashely, and their Welsh Terrier, Posey.

Areas of Practice

  • Probate and Trust Administration

Bar Admissions

  • Massachusetts, 1981
  • U.S. District Court District of Massachusetts, 2001


  • Western New England College School of Law, Springfield, Massachusetts
    • J.D. – 1981
  • Smith College
    • B.A. – 1977
    • Major: Political Science

Past Employment Positions

  • Sentry Insurance, Assistant General Counsel, 1982 to 1985
  • American Mutual Insurance Company, Assistant General Counsel, 1985 to 2007