A new study says Minnesota leads the nation in ex-convict recidivism, concluding that 61 percent of prisoners released in 2004 were back behind bars within three years for committing new crimes or for violating terms of their release.

The national average was 43 percent (based on 41 states reporting), according to the report, released Wednesday by the Pew Center on the States.

Minnesota corrections officials immediately challenged the data, arguing that "recidivism" should not include offenders that Minnesota sends back to prison for rules violations, such as drinking alcohol or failing to call their parole officers.

"Combining technical violations like use of alcohol with statistics on new crimes is inherently misleading," state Corrections Commissioner Tom Roy said in a statement Wednesday.

But Minnesota also came in high, No. 4, for offenders returned to prison for committing new crimes, the report said. The Pew researchers put that number at 36 percent; Minnesota officials said a more accurate figure is 23.4 percent.

Roy said, however, that variations in corrections policy from one state to another can explain some of the difference in return rates -- a point acknowledged in the Pew report.

Minnesota, for example, has the nation's second-lowest prison incarceration rate, with 9,429 offenders serving time in prison. By comparison, Wisconsin incarcerates 23,749 offenders. That means, according to state officials, that Minnesota reserves its prison space for high-risk offenders, who are more likely to get in trouble after release than are lower-risk criminals.

"When you're sent to prison in Minnesota, you've earned your place there," Roy said. "That population of offenders is simply at greater risk of re-offending after release."

Revolving door?

The study, titled "The Revolving Door of America's Prisons," was conducted to review the success of state corrections strategies after three decades of skyrocketing prison populations and costs. The report noted that state prison populations have grown eightfold since 1973, far faster than population growth, and that spending on corrections has quadrupled in the last two decades, making it the second-fastest-growing component of state budgets after health care.

Minnesota was one of 15 states whose recidivism rates rose between 1999 and 2004, the report said, while 17 states reported falling rates.

Wyoming and Oregon had the lowest overall recidivism numbers for offenders released in 2004, with rates hovering below 25 percent. Topping 50 percent were Minnesota, Alaska, California, Illinois, Missouri and Vermont.

The rate in Kansas dropped by more than 22 percent between 1999 and 2004, while it jumped by about 35 percent in South Dakota over the same period.

Staff writer Paul McEnroe and the Associated Press contributed to this report. Paul Walsh • 612-673-4482