This Cannot Be True

From a Newsweek article about the bizarre murder trial of an American woman in Italy: 

Police statistics saying that nearly two-thirds of violent crimes in Italy are carried out by immigrants have triggered a wave of resentment against the new residents.

According to this NPR story, there are between 4 and 5 million immigrants living in Italy. The "statistics" suggest that 7 percent percent of the population are responsible for 67 percent of the violent crime. That defies credulity. And it's not like Italy was a famously crime-free nation before immigration kicked up.