I enjoy the challenge of trying to resolve complicated problems for clients. The objective is always peace, and whether that peace comes through early resolution, intense discovery or trial, achieving it is fulfilling. At all times during the process the client’s emotional perspective matters, and it always guides my advice and approach.

Matthew J. Rossiter brings a wealth of experience to his clients in the areas of fiduciary litigation, civil litigation, estate planning and probate administration at Lathrop GPM. With a strong focus on resolving complex disputes, Matt has built a reputation as a trusted advocate for individuals and businesses alike. A member of the Private Client Services group, Matt has tried nearly every type of case related to trusts, estate planning and administration, including trust contests and appellate matters involving trust interpretation and validity, reformation due to mistake, probate and trust administration, guardianship and breach of fiduciary duty. He has also drafted many estate plans and managed their administration.

Matt’s ability to handle nuanced legal disputes stems from years of trial experience and a deep understanding of the law. His practice spans courts across Missouri and Illinois. Matt represents a diverse client base including:

Clients benefit from Matt’s extensive courtroom experience, dedication to protecting their interests and ability to navigate challenging disputes with skill and precision. From guiding families through emotionally charged probate matters to representing business owners in high-stakes civil litigation, Matt approaches each case with care, diligence and a commitment to achieving positive outcomes.

Matt’s legal influence extends beyond the courtroom. A frequent speaker on fiduciary litigation, he has shared valuable insights at seminars and conferences, equipping both attorneys and fiduciaries with practical guidance. He is a founder of the annual Fiduciary Litigation Seminar sponsored by the Bar Association of Metropolitan St. Louis, where he has frequently presented or moderated.

When working with Matt, clients gain more than legal representation—they build a partnership with a seasoned attorney who is deeply invested in their success and peace of mind.

When asked…

Why did you become a lawyer?

After college I worked on the trading floor at the Chicago Board of Trade. It was a regulated environment with many rules. During breaks on the trading floor I read “The Man to See” about Edward Bennett Williams, the legendary trial attorney. I became fascinated with the intersection of trial work, business and politics. I decided to go to law school. My passion comes from duty: clients hire you because they need help. Providing that help to the best of my ability is fulfilling.

What do you do outside of work?

I exercise, chase our four children, follow basketball, football, baseball and boxing, listen to blues-based music, and search for good wine.

Areas of Focus

Services

Experience

  • Successfully defended a trustee at trial who was sued for breach of fiduciary and prevailed on counterclaim for reformation based upon mistake. The case was upheld by the Missouri Court of Appeals.
  • Represented a trust beneficiary in two separate cases involving breach of fiduciary duty and trust interpretation, each time prevailing at trial and in the Illinois Court of Appeals.
  • Represented a defendant sued in Illinois and Tennessee for breach of contract related to an antenuptial agreement and prevailed in both trial courts, successfully resolved case post-appeal.
  • Twice prevailed at trial on behalf of plaintiffs in trust contests involving lack of capacity, undue influence, and family farms.
  • Participated in the complex estate planning for a successful real estate investor and business owner with a plan that properly utilized distributions and a no contest clause to achieve the decedent's objectives of providing for his spouse, avoiding unnecessary and costly litigation, and estate tax savings.
  • Successfully represented a Trust Company in matters involving family acrimony related to a second spouse, loans and alleged improper encroachments upon trust assets. The resolution provided complete vindication of the Trust Company's administration.

Credentials

Education

  • Saint Louis University School of Law (J.D., 1994)
  • Marquette University (B.S.B.A., 1990)

Admissions

Bar Admissions

  • Missouri, 1994
  • Illinois, 1995

Court Admissions

  • U.S. District Court for the Eastern District of Missouri, 1994

Recognitions

  • Missouri & Kansas Super Lawyers, 2010-2024
    • "Top 50: St. Louis," 2013-2022, 2024
    • "Top 100: Missouri & Kansas," 2013-2014, 2018-2020, 2024
  • St. Louis County Bar Association, Outstanding Young Lawyer Award, 2005
  • E.A. Mellinger Foundation Scholarship Recipient, 1986-1990, 1991-1994

Presentations

  • Speaker, "Lessons from a Loser," Fiduciary Litigation, The Bar Association of Metropolitan St. Louis, 2019
  • Moderator, "Fiduciary Litigation," The Bar Association of Metropolitan St. Louis, 2017
  • Speaker, "Diversity and the Non-Partisan Court Plan," The Bar Association of Metropolitan St. Louis, 2016
  • Speaker, "How To Be a Judge," The Women Lawyers' Association of Greater St. Louis, 2016
  • Speaker, "Recent and Pending Legislative Initiatives in Trusts and Estates," and "Case Law Developments," The Bar Association of Metropolitan St. Louis, 2015
  • Speaker, "Update on the Law," Fiduciary Litigation, The Bar Association of Metropolitan St. Louis, 2006-2012, 2015
  • Speaker, "The Lawyer's Estate Plan File in Litigation," The Bar Association of Metropolitan St. Louis, 2014
  • Speaker, "Terminating Trusts and Making Final Distribution Without Getting Sued," Fiduciary Litigation, The Bar Association of Metropolitan St. Louis, 2013
  • Speaker, "Last Minute Estate Planning," The Bar Association of Metropolitan St. Louis, 2005
  • Speaker, "Choice of Document: Trust or Will," The Bar Association of Metropolitan St. Louis, 2003
  • Speaker, "Representing Personal Representatives and Conservators," The Missouri Bar, 2002
  • Speaker, "Administering the Guardianship and Conservatorship Estate," St. Louis County Bar Association, 2002
  • Speaker, "Probate for the Living," St. Louis County Bar Association, 2001
  • Moderator, "Liens in Personal Injury Cases," The Bar Association of Metropolitan St. Louis/Lawyers Association of St. Louis, 2000
  • Speaker, "Probate and Trust," UMKC Annual Law Update, 1998-2002

Publications

  • The St. Louis Bar Journal, "Burdens of Proof in Missouri Estate and Trust Litigation," Spring 2016
  • The St. Louis Bar Journal, "Representing Claimants in Probate Estates: Bad Things Can Happen to Good Lawyers," Fall 2003

Professional Activities

  • Illinois State Bar Association
  • Louis County Bar Association
  • The Bar Association of Metropolitan St. Louis (BAMSL)
    • Probate and Trust Steering Committee, Current Member and Former Chair
  • The Lawyers Association of St. Louis
  • The Missouri Bar
  • Twenty-First Circuit Judicial Commission, Commissioner, 2011-2017

Community Involvement

  • Almost Home, Inc., Board of Directors