(CBS/AP) WASHINGTON - The number of adults behind bars, on parole, or on probation in the U.S. was at its lowest level in 11 years in 2011, according to a new justice department report.
The Bureau of Justice Statistics released it's findings Thursday, revealing that last year the number of people under some kind of supervision by federal, state or local corrections officers decreased by 98,900, or 1.4 percent, the third straight year of decline.
In 2011, 6.98 million adults, or 2.9 percent of the population, were under some kind of law enforcement supervision.
About 7 in 10 people in the corrections system were on probation or parole, with the remainder behind bars.
James Alan Fox, a professor of criminology, law and public policy at Northeastern University, said the reduction reflects the cumulative impact of lower crime rates.
"There is a lag between crime drops and correctional drops because of the length of sentences being served," he said. "It is likely that the correctional population will continue to decline as releases outpace admissions."
The overall decrease was fueled mostly by a drop in the number of people on probation, which fell below 4 million for the first time since 2002. The number of people incarcerated also dropped slightly.
One area that saw a small increase was the number of people on parole. Although the number of people who entered parole decreased last year, that was more than offset by few people leaving parole.
Fox said the overall downturn also reflected tight budgets and limited space, which have forced authorities to release certain offenders early.