About Denner Lamanna
Boston trial and appellate counsel for consequential cases.
We are a selective litigation firm. We take fewer matters so founding partners and senior trial counsel can stay inside the fight—from the first sign of trouble through trial and appeal.
Serious problems require serious lawyers. That’s what we do.
The firm
Built for the cases that matter most.
Denner Lamanna is the practice of founding partners Jeffrey A. Denner and Jennifer Lamanna—trial and appellate counsel for individuals and organizations facing criminal exposure, government investigations, civil rights violations, business disputes, family crises, catastrophic injury, and other high-stakes litigation.
For more than fifty years, Mr. Denner has concentrated on complex, often high-profile defense across the United States and internationally, including selected civil matters for people whose civil rights have been violated by the government. His representation begins at the investigative, pre-indictment stage and carries through trial, appeal, and post-conviction where the case demands it.
Attorney Lamanna brings more than twenty-five years of litigation before Massachusetts Superior Court, the Appeals Court, and the Supreme Judicial Court—counsel to families, professionals, and institutions when the stakes are financial, parental, or existential. Her reported appellate work includes landmark parentage and First Amendment decisions that changed the rules for everyone who came after.
A Boston-based law firm serving clients across New England, nationwide, and internationally. Our office is minutes from the state and federal courthouses, and we appear in state, federal, military, and coordinated forums where licensing permits.
Founding partners
The lawyers who lead the work.
Senior counsel stay involved. The lawyer in the strategy room is the lawyer in the courtroom.
Founding Partner · Trial counsel
Jeffrey A. Denner
Fifty-plus years defending complex, often high-profile cases for individuals and organizations across the United States and internationally. Yale College. Harvard Law School. Trials and appeals in roughly 35–40 jurisdictions across four continents.
Full biography
Founding Partner · Appellate & trial
Jennifer Lamanna
Twenty-five-plus years before Superior Court, the Appeals Court, and the Supreme Judicial Court. Counsel on reported decisions that reshaped Massachusetts parentage law and struck down unconstitutional prior restraints on speech.
Full biographyThe problems we handle
Serious criminal and civil litigation. Business disputes. Investigations. Appeals.
We represent clients when the ordinary approach isn’t enough.
- Serious criminal mattersInvestigations, charging decisions, trial, and appeal.
- Civil rightsGovernment overreach, constitutional injury, accountability.
- Serious injuryCatastrophic harm and wrongful death.
- Family mattersHigh-conflict family, parentage, and DCF exposure.
- Business disputesCommercial conflict with real consequences.
- Military exposureCourts-martial and related proceedings.
- Appellate litigationAppeals Court, SJC, First Circuit, and beyond.
How we approach serious problems
First, we figure out what you’re up against.
Every serious legal problem is different. Before we recommend a course of action, we identify the facts, the vulnerabilities, the leverage, and the risks.
Then we build the strategy.
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Assess
Understand the problem. Find what matters.
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Strategize
Identify leverage. Build the strongest path forward.
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Act
Negotiate, litigate, try, or appeal—with purpose.
Legal impact
We’ve changed the law.
Cases that changed the rules
Some cases resolve a dispute. Others change the rules for everyone who comes after.
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Matter of Extradition of Howard
791 F. Supp. 31
Jeffrey A. Denner
A landmark U.S.–U.K. extradition proceeding addressing the scope of appellate review and a defendant’s treaty-based right to appeal.
Read the case -
Partanen v. Gallagher
475 Mass. 632
Jennifer Lamanna
The SJC clarified the circumstances under which a non-biological parent may establish presumptive parentage.
Read the case -
Shak v. Shak
484 Mass. 658
Jennifer Lamanna
The SJC struck down sweeping divorce-related nondisparagement orders as unconstitutional prior restraints.
Read the case -
Guinane v. Chief of Police
24-P-1442
Jeffrey A. Denner · Edward M. Gainor
The Appeals Court rejected a firearms-license denial based on the conduct of the applicant’s spouse and clarified the statutory standard governing applicant suitability.
Read the case
View all published decisions Attorney advertising. Prior results do not guarantee a similar outcome.
Where we appear
State. Federal. Military. International.
Litigation counsel at every stage—from strategy and filing through trial and appeal.
- Massachusetts Superior and District Courts
- Appeals Court & Supreme Judicial Court
- U.S. District Court for the District of Massachusetts
- U.S. Court of Appeals for the First Circuit
- U.S. Supreme Court
- U.S. Court of Appeals for the Armed Forces
- Administrative, licensing & disciplinary boards
- Coordinated national & international forums
Next step
You have a serious problem.
Let’s figure out what to do about it.
A phone call is always best. Call (617) 886-5188.