About Kazarosian Costello & O'Donnell LLP

A Premier Massachusetts And New Hampshire Legal Team

Marsha V. Kazarosian, Walter A. Costello, Jr. and Kathleen M. O'Donnell formed Kazarosian Costello & O'Donnell LLP, combining their accumulated experience and legal skills to become the premier law firm representing clients in Massachusetts and New Hampshire.

Each of our principal attorneys has more than 30 years of legal experience. We have the knowledge and experience to provide sound case assessments, intelligent litigation strategies and aggressive, smart representation. Whether at the negotiating table or in the courtroom, we can help you get the results you need.

Meet Our Attorneys

Our principal attorneys are the core of our legal practice.

Marsha V. Kazarosian

  • President-elect Massachusetts Bar Association
  • Past president Massachusetts Academy of Trial Attorneys
  • Past president Essex County Bar Association
  • Named to the Massachusetts Super Lawyers list
  • Named Top Woman in the Law in Massachusetts

Walter A. Costello, Jr.

  • Past president Massachusetts Academy of Trial Attorneys
  • Past president Essex County Bar Association
  • Named one of the Best Lawyers in America
  • Who's Who in American Law
  • Named to the Massachusetts Super Lawyers list

Kathleen M. O'Donnell

  • Past president Massachusetts Bar Association
  • Past president Massachusetts Academy of Trial Attorneys
  • Past president Greater Lowell Bar Association
  • Named to the Massachusetts Super Lawyers list
  • American Board of Trial Advocates
  • Who's Who in American Law

Follow the links below to learn more about our attorneys.

Working Together To Serve Our Clients And Our Community

We formed KCO to become a strong collective force for our clients and to pass on to the next generation of lawyers the skills to represent individual clients and the desire to protect our system of justice.