Murder rates in four of the nation’s big cities have returned to levels not seen since the 1990s, an alarming surge that police officials are struggling to slow even as crime nationally is near historic lows.

A Wall Street Journal analysis of homicide data since 1985 for the 35 largest cities shows that four—Chicago, Baltimore, Milwaukee and Memphis, Tenn.—have in the past two years approached or exceeded the records set a quarter-century ago, when cities across the country were plagued by gang wars and a booming crack trade.

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