Partner

Joni Katz Mackler

Overview

Joni Katz Mackler is a Partner at CMBG3 Law and is licensed to practice in Massachusetts.

Joni brings to the firm 35 years of experience as a litigator handling complex cases with an emphasis on defending toxic tort and product liability matters. She has handled matters involving asbestos, lead paint, latex, pesticides, mold, carbon monoxide, diesel exhaust, benzene, and other chemicals.

Joni has managed all aspects of the litigation process, from discovery and motion practice to trial, negotiations and mediations. She has extensive experience waging Daubert-Lanigan challenges of plaintiffs’ medical and scientific experts, and is particularly skilled at researching and writing briefs on complex medical, scientific and technical issues and participating in evidentiary hearings. Joni is knowledgeable about the FELA, and has served as defense counsel to a New England-based railroad for many years in connection with asbestos and other toxic tort litigation. In this capacity, she now serves as local counsel for the Class I freight railroad company which acquired this New England-based railroad in 2022. During her career, she has also defended general product liability and civil litigation matters, including claims involving employment, construction defects and accidents, and premises liability.

Prior to joining the Firm in 2026, Joni initially practiced in the litigation departments of two Boston-based firms – Burns & Levinson for eight years and Curley & Curley for fourteen years – followed by thirteen years in the Wellesley, MA office of a Hartford-based firm with heavy focus on defending product manufacturers and distributers in asbestos litigation matters. During this time, Joni gained proficiency conducting numerous depositions of parties, fact witnesses, and expert witnesses in asbestos litigation, and developed a deep knowledge of a variety of products and the applicable science. She has also focused on actively working with National Coordinating Counsel to develop strategies for the effective management of current and future litigation.

Outside of the office, Joni enjoys yoga, skiing, family-time and family vacations, and dancing to live Grateful Dead cover bands.

Accreditations

Education

  • Boston College Law School, JD 1990 cum laude
  • Cornell University, BS 1985

Admissions

  • Massachusetts
  • US District Court for District of Massachusetts

Honors

Peer Review Rating

  • Martindale-Hubbell AV® Preeminent™

Professional Organizations

  • Defense Research Institute

In the Media

News

Joni Mackler was selected by MCLE to author the chapter “Contribution and Indemnity” for the 2017 edition of the Massachusetts Tort Law Manual, published in July 2017. The MCLE Press subscriber letter highlights that this third revised addition of the Massachusetts Tort Law Manual includes extensive revisions to the book’s discussion of contribution and indemnity. See Chapter, “Contribution and Indemnity”, Massachusetts Tort Law Manual (MCLE, Inc. 3rd ed. 2017). MCLE requested Joni Mackler to author updates for this chapter for the 4th edition published in 2021 and the 4th edition supplement published in 2024.

Publications

Published Articles

  • Chapter, “Contribution and Indemnity”, Massachusetts Tort Law Manual (MCLE, Inc. 3rd ed. 2017, MCLE, Inc. 4th ed. 2021, and MCLE, Inc. 4th ed. 2024 Supplement).
  • Presenter/Article “Defending A Multiple Chemical Sensitivity Case In The Courts”, Multiple Chemical Sensitivity Cases and Daubert (MCLE, Inc. 98-17.10-CM).
  • “Law of Scientific and Technical Evidence and Working with Experts”, The Best of MCLE Journal, Vol. 6, No. 3 (May 1995).
  • “Hazardous Working Conditions and Fetal Protection Policies: Women Are Going Back to the Future.” Boston College Environmental Affairs Law Review, 17 (1989): 201-30.