Mayer Brown (Photo by Diego Radzinschi/ALM)

Stephen Shapiro, the founder of Mayer Brown‘s U.S. Supreme Court practice, was shot and killed at his home in a northern Chicago suburb on Monday night, according to police.

A suspect in what police said was a domestic-related shooting was taken into custody about three hours after the incident. That suspect, who has yet to be identified, fled Shapiro’s home in Northfield, Illinois, and barricaded himself in his apartment in nearby Winnetka. His arrest occurred following a brief standoff with a SWAT team, according to local reports, and police said they expected charges to be filed against the suspect.

“We are shocked and saddened to learn of the death of Steve Shapiro, our friend and colleague,” a Mayer Brown spokesman said in a statement from the firm that noted Shapiro’s role as “one of the most accomplished appellate lawyers” in the U.S. “Our thoughts are with Steve’s family at this difficult time,” Mayer Brown said.

A Cook County Medical Examiner’s report released late Tuesday said the cause of death was a homicide due to multiple gunshot wounds.

Stephen Shapiro

Shapiro, 72, once served as U.S. deputy solicitor general during the Reagan administration. He is also credited with founding Mayer Brown’s Supreme Court and appellate practice. In front of the country’s highest court, Shapiro has argued 30 cases and personally briefed more than 200.

Shapiro joined Mayer Brown in 1972 and made partner in 1978. He then left to serve in the Solicitor General’s Office. Shapiro rejoined Mayer Brown in 1983 to start what was possibly the first private practice in Big Law dedicated to arguing before the nation’s highest court.

“He was certainly one of the creators of what has now become a much more specialized Supreme Court bar,” said Sidley Austin chairman emeritus Carter Phillips, who overlapped with Shapiro in the Solicitor General’s Office and competed with him as a veteran Supreme Court practitioner.

Phillips said Shapiro was respected for his “sheer determination and energy,” producing “awe-inspiring” amounts of quality work product.

“He would make changes on the brief before the last possible second when you’d have to say, ‘Steve, this has got to get printed, we can’t make any more changes,’” Phillips said. “He was a great lawyer.”

Shapiro’s death was greeted with an outpouring of support among appellate lawyers on social media and elsewhere.

“Our appellate community is a small and tight-knit group of highly specialized practitioners,” said Ian Heath Gershengorn, chair of Jenner & Block’s appellate and Supreme Court practice.   “We mourn Stephen Shapiro’s loss. He was a giant in the field and we recognize his many important contributions to the appellate profession and community. Most importantly, our hearts go out to his family and friends, and especially to our colleagues at Mayer Brown.”

Shapiro was joined at Mayer Brown in 1986 by Andrew Frey and Kenneth Geller, who also came out of the Solicitor General’s Office. The group went on to form one of the largest and busiest Supreme Court practices in the U.S. Reuters reported in 2014 that Mayer Brown had more petitions granted at the nation’s top court than any other major firm between 2004 and 2012.

Shapiro was also known for his work as the author of the treatise “Supreme Court Practice,” which is now in its 10th edition and has been referred to as “the Bible” of Supreme Court practice by justices themselves.

Timothy Bishop, a Mayer Brown partner in the firm’s Supreme Court practice who worked two offices down from Shapiro, said that his former colleague had recently handed in his chapters for the 11th version of that treatise.

“If I’ve ever worked with a lawyer who deserved the description of genius, I think it was Steve,” said Bishop, who worked with Shapiro on a daily basis beginning in 1991.

Shapiro said in a 1997 interview that his preparation for cases involved reading the entire record of a new appeal. He was helped in that endeavor by teaching himself to “speed read,” Bishop said. Within two days of receiving a new matter, Bishop said Shapiro would begin sending out “a barrage” of memos on the relevant cases and most pressing arguments.

“I know when I started I’d always be thinking, ‘Well, no one could get into a case that quickly,’” Bishop said. “Then you’d go back at the end of the case and look at the emails and realize he’d captured the winning arguments right from the very start. I still don’t understand how anyone could do that. He just had a very accurate and rapid grasp of what would win that appeal.”

Bishop said the death of a mentor whom he’d worked with for three decades would be a “deep personal loss.” But he credited Shapiro for fostering a collaborative environment among the appellate team at Mayer Brown.

Timothy Bishop

“Steve always said he founded the practice, but he wasn’t the head of the practice in anything other than title,” Bishop said. “This was a practice of equals.”

Shapiro’s self-described strategy for building the 60-plus member appellate unit at Mayer Brown was to replicate the Solicitor General’s Office for private clients. That involved hiring the most talented lawyers out of that office in addition to prominent academics and focusing on specialization of substantive areas of law. His views on specialization showed why he encouraged young lawyers to seek out new practice areas.

“I see young lawyers today developing specialties in the law that give them tremendous name recognition, [and] that create tremendous client demand,” Shapiro said in 1997. “Their judgment on very big issues becomes vital to businesses and other clients while these individuals are still very young and it is precisely because they have specialized and studied a narrow but important field of law.”

In one of his more recent Supreme Court appearances, Shapiro argued on behalf of the Mayo Clinic in a case that resulted in a 2012 unanimous ruling against Prometheus Laboratories Inc. The closely watched case involved patents on laboratory tests.

Shapiro’s last oral argument occurred less than two weeks ago. On Aug. 2, Shapiro argued on behalf of Whirlpool Corp. before the U.S. Court of Appeals for the Sixth Circuit in a long-running case involving a retiree benefits dispute.

It was a final example of a long-running irony of Shapiro’s corporate-focused legal practice. He was the grandson of a labor organizer and politician in Chicago and his late father, Samuel Shapiro, was a union lawyer.

Shapiro is survived by his wife, Joan Gately Shapiro, and daughter, Dorothy Shapiro Lund, a former Sullivan & Cromwell associate who is now an assistant professor at the University of Southern California Gould School of Law. A son, former Chicago comedian Michael Shapiro, died in 2015.

A memorial service for Shapiro will be held at 4 p.m. on Monday, Aug. 20, at Christ Church in Winnetka, Illinois.