New York City passed a whole day without a single report of a person being shot, stabbed or subjected to any other sort of violent crime for the "first time in memory", police said.
Monday was symbolic as it came towards the end of a year in which the city's murder rate is on target to hit its lowest point since 1960, according to New York Police Department chief spokesman Paul Browne.
While crime is up 3% overall, including a 9% surge in grand larceny that police attribute to a rash of smart phone thefts, murder is down 23% over last year, the NYPD said.
As for a day without violent crime, experts said they could not recall that happening in recent memory.
Tom Repetto, author of American Police 1949-2012, said "In a city of 8 million people, this is extremely rare."
There have been 366 murders in the city so far this year, compared with 472 at this time last year, according to the NYPD. In 1990 the figure was somewhat higher at 2,300 murders.
The introduction of zero tolerance policing during the term of Mayor Rudy Giuliani and police Commisioner Bill Bratton in the early 1990s has been credited with beginning the drop to present crime rates.
Mr Repetto attributed New York's success to "pro-active" police department tactics, including its controversial stop and frisk policy.
While critics have charged that the dramatic increase in stops has not led to a similar rise in gun seizures, police officials have countered that proactive tactics have made criminals think twice about taking their guns out on the street.
By comparison, Chicago, Illinois, a city of about 2,707,000 people that has been plagued by gang violence in 2012 , has registered 462 murders so far this year, according to the Chicago Police Department.
In Philadelphia, a city of about 1,536,000 people, there have been 301 murders so far this year, the exact same number as this time last year.
Washington DC has also been successful in cutting down on violent crime during this year. The US capital is on track to finish the calendar year with less than 100 murders, which during the peak of murders in the area would have been unimaginable.