CHICAGO (CBS) — New numbers from the FBI show that violent crime is up for the second year in a row, driven by what’s happening in urban centers such as Baltimore, Las Vegas and Chicago.

Still, some experts warn against jumping to conclusions.

John Pfaff, a Fordham University law professor and economist, says about 20 percent of the national homicide increase was just in the city of Chicago. However, he added that about half of the rise in murders in Chicago took place in just five neighborhoods.

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“In other words, five neighborhoods in Chicago explain 10 percent of the national increase in homicide rates,” Pfaff said. “Crime is incredibly geographically conscience — not just Chicago verses other cities, but even within Chicago.”

Therefore, Pfaff says, when President Trump rhetorically asked repeatedly what’s going on in Chicago, the answers are concentrated in nine percent of the city’s population, and not prone to national analysis or easy answers.