Peter Scharf, executive director of the Center for Society, Law and Justice at the University of New Orleans, estimated that there were as many as 20,000 participants in the drug culture in the city before the storm. Those drug users and dealers were the engines of the city's crime, Mr. Scharf said, but are now largely absent. No one is certain where they wound up.
Federal agents and police officials elsewhere say there have not been any noticeable spikes in crime in the cities that took in large numbers of hurricane refugees, including nearby Baton Rouge, Houston, Dallas, Atlanta and other cities in the Southeast.
What is known is that many of the most impoverished, crime-ridden sections of New Orleans remain largely empty, in part because the expense of returning and repairing homes is beyond the means of previous residents. There is no precise precedent for this transformation in the crime rate, law enforcement officials and academic experts say. While the few residents who have returned are holding their breath to see how long it lasts, the sudden change has become a subject of intense interest for those who study crime.
"This is one of the most interesting experiments in crime we've ever seen," Mr. Scharf said. "Without effective courts, corrections or rehabilitation, we have reduced the crime rate by 100 percent."
