New York, Chicago and Washington all experienced significant declines in homicides in 2017, though the murder rate rose in Baltimore, Maryland, amid drug problems and lingering racial tensions.
And while its number of murders was down, Washington saw some particularly brutal killings, including a gruesome decapitation blamed on a gang, and authorities in every city said they still had much work to do.
The homicide decline was dramatic in New York, which experienced 2,245 killings as recently as 1990 but just 286 in 2017 as of December 27, according to The New York Times.
That was down from 334 in 2016 and represented the city's lowest number of murders since the 1950s.
Every major category of crime declined there, from rape to car theft, the Times reported. Indeed, violent crime in the city has declined for 27 straight years.
Chicago, which in 2016 suffered through its deadliest year in two decades with 754 killings, saw its murder total drop last year to 650, the largest year-to-year decline since 2004, the Chicago Tribune reported.
Anti-police sentiment there fueled a surge in violence after the 2016 release of a video showing a white police officer fatally shooting a black teenager.
President Donald Trump has repeatedly castigated Chicago authorities for letting violence run "out of control."
But police superintendent Eddie Johnson told the Tribune that new technology and tactics, the hiring of 1,000 additional police officers, and efforts to improve police-community relations had helped lower total shootings. Arrests for gun crimes were up by 27 percent.
Building 'on the progress'
"None of us are satisfied," Johnson said in a statement, promising in 2018 to "build on the progress we made last year."
Homicides fell in Washington from 135 in 2016 to 116 in 2017. That returns the city to a level seen before a spike two years ago.
Mayor Muriel Bowser said her city had stepped up efforts to mediate disputes and prevent retaliation after shootings, while working with non-police agencies to help calm neighborhoods.
But there have been some vicious killings of area teens. One boy was shot in an apparent robbery of his Air Jordan sneakers; a 17-year-old girl was fatally attacked by a stranger as she walked to a mosque during Ramadan; and a teen in suburban Maryland was brutally stabbed and decapitated, allegedly by members of the MS-13 gang.
And Baltimore, which experienced violent riots after the 2015 death of 25-year-old Freddie Gray while in police custody, had at least 343 homicides last year, up from 318 killings the year before, the Baltimore Sun reported.
That left the drug-plagued city of 620,000 with more murders last year — per capita — than New York experienced with its 8.4 million residents.