NEW YORK (CBSNewYork) — Longtime Manhattan District Attorney Robert Morgenthau has died at 99 years old.

A pillar of the New York justice system, Morgenthau prosecuted many high-profile cases during his 35 years in office.

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CBS2’s Jenna DeAngelis has a look back at his life and career.

It’s hard to sum up a life of nearly 100 years, especially that of Morgenthau, a Navy veteran, a prosecutor and philanthropist, who lived a life of public service.

“Our system of justice is based upon the belief that no man can escape answering for his actions,” Morgenthau once said.

Former Manhattan DA Robert Morgenthau and his wife, Lucinda Franks (credit: CBS 2)

The 99-year-old made history as Manhattan’s longest-serving district attorney. Staff referred to him as “The Boss.” And that he was, spending more than three decades jailing criminals from mobsters to murderers, until he retired in 2009.

Prior to that, he served as U.S. Attorney for New York’s Southern District during the Kennedy and Johnson administrations.

Subway vigilante Bernard Goetz was one of his most notable prosecutions. He also got a conviction in the case of John Lennon’s killer, Mark David Chapman.

On top of that, Morgenthau developed a reputation for going after white-collar criminals.

He had a reputation that was so strong, he became the inspiration for “Law and Order” character Adam Schiff, played by Steven Hill.

Current Manhattan District Attorney Cyrus Vance praised his predecessor’s “unimpeachable integrity, unflinching courage, unyielding independence, and fierce devotion to equal justice under the law” in a statement Monday.

“During his legendary 35-year career as Manhattan District Attorney, Robert M. Morgenthau’s unimpeachable integrity, unflinching courage, unyielding independence, and fierce devotion to equal justice under the law set the gold standard for distinguished public service across the nation. His incredible tenure as District Attorney, stretching from 1975 to 2009, sparked a paradigm shift among his prosecutorial peers that emphasized proactive strategies, diverse hires, and increased community engagement. His crime-fighting strategies also played an important role in facilitating New York City’s remarkable decline in homicides and violent crime – and its current status as America’s safest big city,” the statement read. “Morgenthau’s extraordinary record of achievements, longevity, and commitment to prosecuting without fear or favor made him the most respected prosecutor of his generation and a hallowed figure among the 2,000 prosecutors he hired. ‘The Boss,’ as he known by staff, was also revered for the genuine interest he took in people’s lives. His guidance launched the careers of a remarkable number of highly influential public servants, including governors, attorney generals, judges, district attorneys, and U.S. Supreme Court Justice Sonia Sotomayor. As such, his impact will live on for generations not only at the Manhattan District Attorney’s Office but throughout the American legal system. He will be deeply missed by all of us who had the honor and privilege of knowing him.”

NYPD Commissioner James O’Neill called Morgenthau, “The most innovative prosecutor in New York City history,” whose vigorous prosecutions helped push the murder rate down 90 percent during his 35 years in office.

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Gov. Andrew Cuomo announced flags will be lowered to half-staff to honor Morgenthau, starting Wednesday.

“I am deeply saddened to learn of the passing of Robert Morgenthau, a true New York hero whose dedication to public service and the law was matched only by the impact he had on the young prosecutors and lawyers like me who worked for him. Mr. Morgenthau was the gold standard of prosecutors and the model public servant, dedicating his life to achieving justice and protecting the public over the course of a storied career as a federal prosecutor under two presidents and as the longest serving Manhattan DA in history. He did his work with humility and integrity, and created the prestige of the DA’s office — and New York is a better place because of him. I keep my assistant district attorney badge from the time I worked for Mr. Morgenthau on my desk as a daily reminder of his unrelenting pursuit of justice,” Cuomo’s statement read. “In honor of Mr. Morgenthau, I am directing flags on State government buildings to be lowered to half-staff starting Wednesday, July 24th until interment. On behalf of the entire New York family, I extend my deepest condolences to Mr. Morgenthau’s family, including his wife Lucinda, his children Jenny, Anne, Elinor, Robert, Barbara, Joshua and Amy and his six grandchildren and three great-grandchildren.”

“This city owes a great debt to Robert Morgenthau. As New York City’s longest serving District Attorney, he presided over an era of extraordinary transformation and inspired generations of public servants. We simply wouldn’t be the safest big city in America today if not for Morgenthau’s decades of dedicated service. His memory will live on as we continue striving toward a fairer criminal justice system,” Mayor Bill de Blasio said in a statement of his own. “My thoughts are with Lucinda and their family during this difficult time.”

Outside the office, Morgenthau was a family man and a father of seven.

Morgenthau lost his first wife in 1972 to cancer. He remarried, Pulitzer Prize-winning journalist Lucinda Franks. Together they appeared on CBS2 in 2014 to talk about her book, which gave a new view on the man she knew differently than the public.

“I wanted people to know his foibles, his strength, his goofiness, his singing, everything he does at home that make him a real person,” Franks said.

CBS2 asked if he missed being district attorney, but its widely known his work never stopped there.

“I’ve got a full plate and I never look back,” Morgenthau said.

“I think my husband is one of the great men of our time,” Franks added.

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Morgenthau’s wife said he passed away Sunday at Lenox Hill Hospital after a short illness and just 10 days shy of his 100th birthday — a life in service to be honored and celebrated.