There have been 1,353 shootings this year, a statistic with comparable records going back to 1994. The previous low was 1,420 in 2009, and the number has dropped by more than 8 percent since last year.
Violent crime hit high points in New York in the 1990s, with a record 2,245 murders in 1990.
While there have been ups and downs since, including a double-digit increase in murders in 2010, the overall drop in crime and violence has helped reshape the city's image. Bloomberg often calls New York the safest big city in America, a description based on FBI statistics for seven major crimes. New York has the lowest rate per 100,000 residents among the 25 most populous U.S. cities.
In Philadelphia, homicides have risen in 2012, despite an overall drop in crime.
Killings in 2012, 335 as of Friday afternoon, will have risen for the third straight year. With a population of about 1.5 million, Philadelphia is less than one-fifth the size of New York.
This year's expected drop in New York murders is "a testament to the hard work and determination of the men and women who put their lives on the line for us every day - and it also reflects our commitment to doing everything possible to stop gun violence," Bloomberg said in a statement as he and Kelly announced the numbers at a graduation ceremony for more than 1,100 police recruits.
In Chicago, Police Superintendent Garry McCarthy said Friday that the city had logged its 500th homicide of the year.
The last time Chicago reached the 500-homicide mark was in 2008, when the year ended with 512 killings. Last year, city records show Chicago had 435 homicides.