While Lawrence Byrne's tenure as the New York City Police Department's top attorney lasted four years, his connections with the country's largest police department, and crime fighting in general, run deep. Byrne is officially stepping down as the NYPD's deputy commissioner of legal matters on Tuesday, capping off an era that, while the safest in the city's history as far as the statistics are concerned, presented significant challenges for the corps of 250 lawyers, civilians and uniformed cops who make up the NYPD Legal Bureau. To name a few: The aftermath of the death of Eric Garner at the hands of an NYPD officer who held him in a chokehold, which was the catalyst for protests across the country and thrust intense scrutiny on the NYPD's use of force policies; numerous legal clashes over a state law that allows the NYPD to keep officer disciplinary records secret and growing scrutiny over the department's surveillance tactics. Byrne called it a “very interesting and challenging time in the policing profession.” “It was an era of record crime reduction and record low crime with a fundamental change in how we policed in partnership with communities around the city,” Byrne said. Byrne has been around long enough to remember a very different New York City, when Times Square was a seedy red-light district and the city was blanketed with thousands of open-air drug markets. It was in this more-dangerous city that Byrne's brother, Edward Byrne, who was a 22-year-old rookie cop in 1988 when he was assassinated in Jamaica, Queens, while protecting a witness against a drug kingpin.   That was the same year that Lawrence Byrne, who clerked for U.S. District Judge Shirley Wohl Kram after his 1984 graduation from New York University School of Law and worked as an associate at Davis Polk & Wardwell, joined the U.S. Attorney's Office for the Southern District of New York to wage his own battle against crime through the courts. From there he went on to serve as deputy chief in the Organized Crime Section of the U.S. Department of Justice Criminal Division.   Before former Police Commissioner William Bratton tapped Byrne in 2014 to head the NYPD Legal Bureau, Byrne worked in Pepper Hamilton's white-collar litigation and investigations group and with Freeh Group International Solutions, an investigative firm founded by former FBI Director Louis Freeh. When Byrne went to work for the Legal Bureau, he was following the footsteps of his father, Matthew Byrne, who became a New York City police officer in 1954 after returning from fighting in Korea. During his 22-year stint with the department, Matthew Byrne worked for the Legal Bureau that his son would eventually lead. Lawrence Byrne cites his father, who died in 2015, as his motivation for becoming a prosecutor. And as for the slain Edward Byrne, every two years Lawrence Byrne appears before the state Parole Board to testify against releasing the four men who were convicted of acting under orders from drug lord Howard “Pappy” Mason to kill the young officer and who were sentenced to 25 years to life. an interview Edward Byrne's memory lives on as the namesake for the Edward Byrne Memorial Justice Assistance Grant, which provides funding for law enforcement agencies across the United States. Lawrence Byrne is returning to the private sector and, while he said he hasn't determined his next step yet, he said he's leaving the department for financial reasons: two of his three children are headed to law school. For the time being, he plans to spend the rest of his summer at his house out in Montauk. “I hope that, and think that, the department and cops know that I advocated very strongly on their behalf,” Byrne said. Following Byrne's announcement earlier in July that he is retiring from the department, Police Commissioner James O'Neill tweeted a statement commending Byrne for his service, calling him the department's “top legal mind” and that Byrne is leaving behind “one of the most remarkable—and truly honorable—legacies of public service ever to be witnessed in all of American law enforcement.”   “Over the past four years in his position as an NYPD deputy commissioner, his guidance has been invaluable,” O'Neill said. “And his family's remarkable efforts over the decades—including Larry's regular trips every two years to testify against his brother's killers at their state Parole Board hearings—have left an indelible mark on each of us and will continue to guide us as we make our way forward together as a police department, and as a city.”