New York City’s top cop announced his retirement Monday after a turbulent three-year run in the high-profile and high-pressure job.

James O’Neill’s announced resignation came on the heels of the firing of former Officer Daniel Pantaleo due to his actions in the incident that led to Eric Garner's death and amid mounting pressure, the New York Post reported.

Dermot Shea, the current chief of detectives, was named by Mayor Bill de Blasio to replace O'Neill.

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O'Neill had been appointed commissioner of the New York Police Department by Mayor Bill de Blasio in 2016, replacing Bill Bratton.

O'Neill, 61, acknowledged the decision three months ago to fire Pantaleo after five years of investigations and disciplinary hearings weighed heavily on him and the department. The city's largest police union called on O'Neill to resign after the firing.

O'Neill said Monday the Pantaleo firing wasn't a factor in his decision to leave, which is set to happen at the end of the month.

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"This job comes with a lot. It comes with a lot of pressure," he added. "This is all I have thought about for the last 38 months — 24 hours a day, 7 days a week. It's all you think about, is keeping the people of this city safe, and it was an honor to serve."

Under his watch, murders hit an all-time low in the first half of 2019 -- though hate crimes and shootings have spiked in the city, the Post reported.

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The New York Times described O’Neill’s tenure as head of the nation’s largest police force as tumultuous. It's a period likely to be remembered for the racially charged aftermath of Garner's death five years ago on Staten Island, an incident that led to Pantaleo's firing in August, a fraught relationship between NYPD leaders and rank-and-file cops and a string of police suicides.

Shea became a New York City cop in the South Bronx 28 years ago. De Blasio said he was "one of the best-prepared incoming police commissioners this city has ever seen."

The Associated Press contributed to this report.