Matthew Segal with the Constitution


Legal Director



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Matthew Segal is Legal Director of the ACLU of Massachusetts, where he leads a team of civil rights lawyers. He has litigated cases on wrongful convictions, police accountability, privacy, the criminalization of poverty, the First Amendment, and immigrants’ rights.

Matt’s cases at ACLUM have temporarily halted President Trump’s first Muslim ban; dismissed over 60,000 drug charges in the Sonja Farak and Annie Dookhan lab scandals; resulted in the release of over 6,000 people from jails and prisons due to the COVID-19 pandemic; yielded the first federal court order requiring someone with opioid use disorder to be provided medication for addiction treatment (MAT) while incarcerated; and made Massachusetts the second state to recognize constitutional protections for cell phone location data.

Matt was named a 2015 Massachusetts Lawyer of the Year by Massachusetts Lawyers Weekly, and in December 2016 he was elected to membership in the American Law Institute. He earned his J.D. from Yale Law School and his B.A., in mathematics and sociology, from Brandeis University. He clerked for the Honorable Raymond C. Fisher of the Ninth Circuit.

Criminal Justice

Privacy & Technology

  • Helped to uncover 63 cases in which the government sought to compel Apple or Google to assist the government in accessing data stored on a mobile device.
  • Argued Massachusetts case holding that state and local police must get a warrant before obtaining two weeks’ worth of a person’s cell site location information (CSLI). Commonwealth v. Augustine, 467 Mass. 230 (2014

Criminalization of Poverty

  • Participated in amicus briefing on the criminalization of poverty in Massachusetts. Commonwealth v. Henry, 475 Mass. 117 (2016); Commonwealth v. Magadini, 474 Mass. 593 (2016).
  • Argued case ending a federal district’s unlawful practice of ordering indigent federal defendants to repay the costs of their court-appointed attorneys. US v. Moore, 666 F.3d 313 (4th Cir. 2012).

First Amendment

  • Filed case challenging a Massachusetts law that requires people to alert the police before exercising their First Amendment right to record police officers performing their duties in public. Martin v. Evans (D. Mass. filed June 2016).
  • Co-counseled successful challenges to anti-panhandling ordinances in Lowell and Worcester, which infringed on the First Amendment right to beg.

Racial Justice & Immigrants’ Rights

  • Argued Louhghalam v. Trump, 2017 WL 386550 (D. Mass. 2017), which for seven days halted President Trump's first Muslim Ban.
  • Led in public records advocacy and amicus briefing in a groundbreaking decision holding that Black men in Boston might have logical reasons to flee the police. Commonwealth v. Warren, 475 Mass. 530 (2016).
  • Argued case on behalf of a U.S. military veteran wrongfully subjected to mandatory immigration detention. Casteneda v. Souza, 810 F.3d 15 (1st Cir. 2015) (en banc).