Michael J. Kennedy, who as a criminal lawyer championed lost causes and deeply unpopular defendants — including John Gotti Sr., Huey P. Newton and Timothy Leary — and finally won freedom for Jean S. Harris, the convicted killer of Dr. Herman Tarnower, the Scarsdale Diet doctor, died on Monday in Manhattan. He was 78.

The cause was complications of pneumonia, which developed while he was being treated for cancer, his wife, Eleanora, said.

A steadfast defender of the underdog and the First Amendment, Mr. Kennedy represented radicals including Rennie Davis, Bernardine Dohrn and Mr. Newton, co-founder of the Black Panther Party. His clients also included the Native American protesters at Wounded Knee, S.D., the family of the rogue real estate heir Robert A. Durst; Mr. Leary, the LSD guru; and Mr. Gotti, the mob boss.

He also represented High Times magazine from its inception (and was later an owner) and shared its agenda to decriminalize marijuana possession. Mr. Kennedy was ranked 46 on the 2014 CBE 100 Most Influential People in the Cannabis Industry list. [Read more at The New York Times]