The United States Penitentiary , Leavenworth, Kansas, was the largest maximum security federal prison in the United States from 1903 until 2005. It became a medium security prison in 2005.

Despite the recession, the historic drop in US crime that began in the early 1990s continues.

In 2009, violent crime in the US fell 5.5% nationwide, marking the third straight year of decline after a longer period of falls earlier in the decade. Murders dipped 7% last year, to 15,100  --  almost 45% below the 1991 peak. And the declines cover nearly every category of crime, in communities big and small. Property crime in 2009 fell 4.9%; robbery, 8.1%; and car theft, 17.2%.

The New York Times reports that in 2009, Chicago had 458 homicides. New York City, which is almost three times as large, had 471, and Los Angeles, which is nearly one and one-half times bigger, had 313. There were days upon days in New York City in 2009 when not a single person was murdered. Two such stretches, in February and March, lasted nearly a week each.

In New York, most of victims in 2009 were killed with a gun fired by someone they knew. Only 34%, no matter how they died, were killed by strangers.

The number of murders in New York in 2009 were at a record low since the modern reporting system was introduced in 1963. The number peaked at 2,245 in 1990.

There is no simple explanation for the dramatic fall in US crime but it remains high compared with Western Europe.

In 1994, William Bratton was appointed New York police commissioner by Mayor Rudolph Giuliani and Bratton adopted a strategy promoted by criminologist George Kelling known as the “broken windows theory”- -  the view that police on the beat could reduce serious crime by also focussing on minor offenses, such as graffiti or vandalised windows, that engenders an anything-goes, Wild West environment. New York City also adopted a “zero-tolerance’’ policy that targeted squeegee men (windshield-washers working the city traffic), the homeless, and petty criminals, to force them off the streets, and sought to take illegal guns out of circulation. A key aspect of the strategy was the idea that most robberies, assaults, rapes, and murders are caused by a small number of hard-core criminals who victimise citizens again and again.

Persistent criminals were identified and locked-up and the US’s imprisonment rate today is four times the world average, with a record 2.3m Americans behind bars. However, states in which prison populations grew the most in the 1990s actually lagged behind the rest of the country in reducing crime. In 2009, the rate of imprisonment slowed and the crime rate also fell.

Some claim reduced lead poisoning and the legalisation of abortion in 1973 were factors. 

It is argued that many young people were suffering the effects of lead poisoning before the advent of unleaded petrol and lead-free paint. As regards abortion, Steven Levitt, co-author of the 2005 best-seller Freakonomics, claimed that the legalisation of abortion in 1973 reduced the number of unwanted babies being born into broken homes, and thus reduced the number of troubled teenagers who reached their crime-prone years two decades later.

The annual US murder rate of five per 100,000 people is down from 9.8 in 1991 but is twice that of France.

Researchers Marianne Junger, Robert West and Reinier Timman, studied the link between aggression, criminality and bad driving. They examined traffic accidents in the Netherlands, using police data to determine if the reckless driver in each crash had a criminal record. They found that drivers who contributed to accidents were much more likely than the general public to have been guilty of violent crime, vandalism, property crime, and serious traffic violations. The authors concluded that aggression and risk-taking do appear to be associated with bad driving.

The authors attribute the apparent link between lawlessness and risky driving to “a general disregard for the long term adverse consequences of [one’s] actions [which] could be labeled risk-taking, impulsiveness, or lack of self-control.”

So the high US imprisonment rate, may also be contributing to improved road driving standards.