During a particularly grim 48 hours in New Haven, Conn., last May, the police reported seven gun incidents, including the shooting of a man who was the father of four young children. These are the kind of numbing crime sprees that have made Connecticut’s second largest city one of the most dangerous urban areas in the country. Yet the crime rate in New Haven is actually declining.

Local governments have been flooded with bad news lately, but one pleasant yet puzzling surprise has been the ongoing drop in the nation’s crime rate. The Federal Bureau of Investigation released its 2010 crime statistics, known as the Uniform Crime Report, which showed that despite the tough recession, the number of violent and property crimes committed dropped for the fourth year in a row. Those cities with 1 million or more residents saw violent crime drop 5.1 percent; cities with populations between 500,000 and 1 million experienced a 5.6 percent drop; and those between 250,000 and 499,999 saw the biggest drop in violent crime, 6.9 percent.

Typically crime rises during periods of high unemployment, such as the one we’re going through now. So what’s going on? Reasons for the contrary trend have crime experts baffled. Michael Maltz, a criminology professor at Ohio State University, told the Cleveland Plain Dealer that the drop in property crime (2.8 percent nationally) could be attributed to people becoming more security conscious, like keeping doors shut with better locks and putting more sophisticated alarms in their cars.

Richard Florida, a senior editor at The Atlantic and a proponent of urban life, zeroed in on the crime decline in cities, especially the largest urban centers with populations of one million or more. Writing on the magazine’s website, Florida speculated that the long-term emphasis on better policing and changing demographics -- prosperous singles, couples, families and empty nesters moving to cities in significant numbers -- could be a factor in “improving neighborhood quality and safety.” But he was quick to note that more analysis of the data was needed before drawing conclusions about the relationship between crime and a city’s social, demographic and economic makeup.

Left unsaid is the fact that while crime in cities has dropped in recent years, the crime rate still remains high. “The national violent crime rate according to the FBI is now the lowest it’s been since 1974,” the Arkansas Democrat-Gazette pointed out. Sounds like good news, “until we’re reminded that the 1974 rate was almost three times what it was in 1960.”

America’s extremely large prison population also presents a problem for cities, where many newly-released ex-offenders end up, often jobless and without resources. When the shooting spree broke out in New Haven in the spring, six of the victims were former prison inmates.

Break that cycle of violence with the right resources, say crime experts, and maybe American cities will finally experience crime rates not seen in 50 years. Until then, the mystery continues.