Here’s a weird and welcome fact: Violent crime rates in the United States have continued to go down despite the deepest and most persistent recession since the Great Depression.

This defies historical precedent and conventional wisdom, which insists that people without jobs have more time and motivation to commit crimes. But in 2010, the last year for which the U.S. Bureau of Justice Statistics has complete data, violent crime — homicides, assaults, robbery — was down 4 percent nationwide.

There may be no single reason for this phenomenon, but one clear factor is that police departments are getting better. A new generation of police officers and commanders has embraced technology and academic research. Researchers, in turn, have learned to embrace the street smarts of patrol officers.

Police departments, here and elsewhere, have harnessed computers and data analysis. They are employing sophisticated new techniques to identify and patrol high-crime areas. Increasingly they are focused on the relatively small number of places where most crime occurs and the relative handful of criminals responsible for most of it.

The LaGrange Department reported closed-case rates higher than national averages in all areas of crime in 2011.

“We’re looking at a decline on everything because we know where we need to be,” Detective Chris Pritchett said.

Pritchett said he credits the city’s decreasing crime rates, in part, to intelligence-led policing — the practice of analyzing trends to predict where and when crimes will happen next — has led to several arrests in recent weeks.

After determining that a series of burglaries near Tower Street were committed by the same suspect, he used factors from each incident to predict the next neighborhood where the suspect would strike next. Police arrested 18-year-old Johnquavious Russell on June 7, just two blocks from where Pritchett predicted.

“It’s proof that crime analysis works,” he said. “We are watching it unfold.”

There are good signs here. In the past, most police departments have been conservative institutions, suspicious of outsiders and slow to change. The city, the courts and cops have shown themselves to be open to innovation and collaboration. The city, and the entire region, will be safer for it.