(BBC) – Chicago saw its deadliest day in at least 60 years last month, with 18 killings within a 24-hour period on 31 May.
The violence occurred as protests over George Floyd’s death in Minneapolis also spurred rioting and looting in the Windy City.
Over the last weekend in May – a three day holiday – 85 people were shot and 24 killed, according to the University of Chicago Crime Lab.
Most of the victims were black.
The dead and injured include students, parents and middle-aged workers, according to the data published in the Chicago Sun-Times.
“We’ve never seen anything like it, at all,” senior research director Max Kapustin told the newspaper, noting that the Crime Lab’s data only goes back as far as 1961.
“I don’t even know how to put it into context,” he said. “It’s beyond anything that we’ve ever seen before.”
Mr Kapustin added that protests over Mr Floyd’s 25 May death in police custody may have distracted Chicago Police Department (CPD) resources from normal patrol duties.
“When CPD has to turn its attention elsewhere and there’s suddenly this vacuum that opens up, you also unfortunately see a picture like you saw with [last] weekend where you see an absurd amount of carnage, people getting injured and killed,” he said.
The second deadliest day in the city’s history was 4 August 1991, when 13 people were killed, according to the data.