Yale Kamisar, a legal scholar whose work on civil liberties and criminal procedure had a profound influence on landmark Supreme Court decisions like Gideon v. Wainwright and Miranda v. Arizona, died on Sunday at his home in Ann Arbor, Mich. He was 92.

His son Gordon confirmed the death.

Professor Kamisar began to wrestle with the issues of criminal procedure — the rules under which the legal system adjudicates crimes — in the late 1950s, as a newly hired faculty member at the University of Minnesota.

At the time, the subject was considered largely a sideshow to the big questions in constitutional law. What few courses existed were sloughed off on new hires, and everyone expected Professor Kamisar to move quickly into teaching antitrust, an area he knew from his time working for a Washington law firm.

Instead, within a decade he established himself as the leading figure in an area of the law that, thanks in large part to his work, suddenly seemed not just important but intellectually vibrant. He continued that work at the University of Michigan, where he moved in 1965.

“He made the subject matter,” Nancy J. King, who teaches criminal procedure at Vanderbilt University and studied under Professor Kamisar at Michigan, said in a phone interview. “He created constitutional criminal procedure as a topic that demanded its own text, and as a field of study.”

The man had met the moment. By the early 1960s the Supreme Court, under Chief Justice Earl Warren, was emerging as a bulwark of civil liberties. And the White House, first under John F. Kennedy and then under Lyndon B. Johnson, was expanding its defense of civil rights, in part by making sure that people of color had legal protections against abuse by law enforcement.

“There was this period of police brutalization of predominantly Black and brown people, especially in the South,” said Eve Primus, who also studied under Professor Kamisar and now holds a chair in his name at Michigan. “Yale, being the person that he was, understood that there were opportunities to move law forward.”

His work was first cited by the Supreme Court in its 1963 decision in Gideon, which established the right to legal counsel in criminal cases. Written by Justice Hugo Black, it was the first of more than 30 decisions over the next half-century to cite Professor Kamisar’s work.

“He was writing articles about what the court should do and what the court had done recently, and they were in turn citing him,” Orin Kerr, a law professor at the University of California, Berkeley, said in an interview.

Professor Kamisar’s greatest impact on the court came in 1966, in its decision in Miranda.

The year before, he had published a lengthy essay in which he compared the American legal system to a gatehouse and a mansion — the gatehouse being the police interrogation room and the mansion being the courtroom.

“The courtroom is a splendid place where defense attorneys bellow and strut and prosecuting attorneys are hemmed in at many turns,” he wrote. “But what happens before an accused reaches the safety and enjoys the comfort of this veritable mansion? Ah, there’s the rub. Typically he must first pass through a much less pretentious edifice, a police station with bare back rooms and locked doors.”

The courts offered extensive protections, rooted in the Fifth Amendment, covering the right against self-incrimination. But no such protections existed in the police station, where interrogators could coerce a suspect to confess.

No system of justice could last long, Professor Kamisar argued, if it relied on the coerced flow of information from the accused. The court agreed. In a decision written by Chief Justice Warren and citing Professor Kamisar’s work, it ruled in 1966 that criminal defendants had to be informed of their rights before being questioned, especially their rights to remain silent and to legal counsel.

That same year Time magazine wrote that “at 37, Kamisar has already produced a torrent of speeches and endless writings that easily make him the most overpowering criminal-law scholar in the U.S.” Others called him the “father of Miranda.”

With the Supreme Court’s imprimatur, Professor Kamisar spent the rest of his career building his chosen field — he co-wrote its leading casebook, “Modern Criminal Procedure” (Professor Kerr later became a co-author) — and defending the Miranda ruling from conservative pushback.

Professor Kamisar’s concern for the vulnerable, and his worries about the reach of government power, motivated his other area of great interest: assisted suicide and euthanasia. If his position on the rights of the accused won him admirers among civil libertarians, many of those same people were flummoxed by his opposition to laws that would seem, on their face, to enshrine an equally important right, over one’s own death.

But in a long run of articles that began even before his work on criminal procedure, Professor Kamisar warned that the legalization of assisted suicide was a slippery slope, and that if doctors were empowered to participate in ending a patient’s life it would be impossible to decide where to draw the line, leading to a world in which active euthanasia was employed against the ill and disabled.

His writings on the subject drew significant attention in the 1990s, when the trials and travails of Dr. Jack Kevorkian, the noted advocate of doctor-assisted suicide, made it a hot-button topic, as did a series of state-level laws legalizing the practice.

“If, as has well been said, ‘the history of our activities and beliefs concerning the ethics of death and dying is a history of lost distinctions of former significance,’” Professor Kamisar wrote in 1993, “what reason is there to think that that history will come to an end when we sanction assisted suicide for the terminally ill?”

Yale Kamisar was born on Aug. 29, 1929 in New York City and raised in the Bronx. His father, Samuel, was a bakery salesman. His mother, Mollie (Levine) Kamisar, was a homemaker.

“He used to talk about himself as a young kid playing stickball in the Bronx, being picked on by cops,” Jeffrey S. Lehman, the vice chancellor of N.Y.U. Shanghai, who studied under Professor Kamisar and later served as dean of the Michigan law school, said in an interview. “And that is sort of what led to his interest in law, as a way to regulate the behavior of powerful people.”

He attended New York University on a scholarship and graduated in 1950. He entered Columbia Law School that fall, but because he had participated in the Reserve Officers’ Training Corps at N.Y.U., he had to interrupt his classes when he was called up to serve in the Korean War.

As a platoon leader, Lieutenant Kamisar entered the fighting just as the Chinese Army was pushing back against early gains made by the Americans and their allies. In one battle, he led a successful charge up what American soldiers called T-Bone Hill, in front of his men and in the face of enemy fire. He was wounded in the fighting and received the Purple Heart, along with several medals for bravery.

Returning to Columbia, he graduated second in his class in 1954. He then went to work in the Washington office of Covington & Burling, a prestigious law firm, where he focused on antitrust law and became an acolyte of Dean Acheson, who had been secretary of state under President Harry S. Truman.

But Mr. Kamisar soon soured on private practice, and after two years he took a job teaching at the University of Minnesota. He retired from the University of Michigan in 2004.

In addition to his son Gordon, he is survived by his wife, Joan (Russell) Kamisar; two other sons, David and Jonathan; his sister, Myrna Berkin; and four grandchildren.