Murders in the U.S. jumped 10.8% in 2015, according to figures released Monday by the Federal Bureau of Investigation—a sharp increase that could fuel concerns that the nation’s two-decade trend of falling crime may be ending.

The figures had been expected to rise, after preliminary data released earlier this year indicated violent crime and murders were climbing. But the double-digit increase in murders dwarfed any of the past 20 years, in which the biggest one-year jump was 3.7% in 2005.

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