Crime is dropping in cities across the United States; experts baffled

The Washington Post reports:

Violent crime has plummeted in the Washington area and in major cities across the country, a trend criminologists describe as baffling and unexpected.

[Washington, DC], New York and Los Angeles are on track for fewer killings this year than in any other year in at least four decades. Boston, San Francisco, Minneapolis and other cities are also seeing notable reductions in homicides.

"Experts did not see this coming at all," said Andrew Karmen, a criminologist and professor of sociology at the John Jay College of Criminal Justice in New York.

Maybe the criminologists are systematically ruling out certain possible explanations.

Maybe if the facts are so baffling to them, they should consider changing their theories.

I keep reading about how the United States has too many people incarcerated. Isn't it possible that our policy hasn't been totally irrational, but is actually working?

Another post for my "experts" tag.