In 2006, state researchers estimated Colorado's prisons would be bursting with 29,443 inmates by 2013.

Now it appears they were off by nearly 8,000 prisoners — off in a good way. Fresher predictions say Colorado will hold only 21,662 people in 2013, part of a steady decline in prison populations nationwide that defies previous recession trends and underlines a systemic decrease in crime.

Those now-nonexistent prisoners would empty the Limon prison eight times over.

Instead of property and drug crime rising with high unemployment and economic desperation, crime rates and incarcerations continue a steady decline. Anti-recidivism efforts by Gov. Bill Ritter and governors in other states appear to be gaining traction in keeping repeat offenders away from expensive prison cells.

"It's an absolutely fascinating period for researchers, because of the break in the pattern we're seeing," said Rick Rosenfeld, a University of Missouri-St. Louis criminologist and president of the American Society of Criminology. "And it's an absolutely heartening period for all of us, because of public safety."

Gov. Bill Ritter and budget officials say the state is already reaping benefits, aside from falling crime rates, through a long-awaited reprieve from constant budget increases. Part of Ritter's February package of deficit-closing proposals included $19.4 million in corrections savings due to lower-than-expected prisoner counts.

At a cost of about $20,000 a year to house a Colorado prisoner, the prisoner shortfall means the state would be spending at least $160 million less than predicted to hold prisoners in 2013.

Ritter, a former Denver prosecutor, said he has watched the number of state prisoners balloon from 3,000 when he began his career in 1981 to beyond 20,000 and to predictions of nearly 30,000 in coming years. The recent drop in projections means "we're doing a lot of things right," Ritter said.

An aging population, smarter recidivism programs, drug courts and parole reforms all contribute to the improvement, he said. The knee-jerk, lock-them-up mentality of politicians and the public has also transformed, Ritter said.

Colorado's crime rate dropped 8 percent in 2008, the third time it had dropped since 2005.

"People have come to understand the intersections with drug addiction and mental-health issues," he said. Ritter added, though, that putting more violent criminals away in the 1980s and '90s also improved crime rates and community stability.

Release program fizzled

State officials and national criminologists emphasize that the Colorado improvements have not come through wholesale early releases of prisoners to cut budgets, as other fiscally challenged states have done. Ritter did propose speeding up the planned releases of some felons last fall, but the program fizzled. Police and others objected to freeing violent offenders even weeks earlier than required, and parole-board decisions have left most terms alone.

Colorado released only three prisoners slightly earlier than mandated in February, and 270 since the fall, said Department of Corrections spokeswoman Katherine Sanguinetti.

Despite periodic national flare-ups over prisoner releases, statistics are moving steadily toward lower crime and increased emphasis on anti-recidivism and drug-treatment programs, said Adam Gelb of the Pew Center on the States in Washington, D.C. Nationally, state prisons held nearly 6 percent fewer people on Jan. 1 than the year before.

Lawmakers and the public are finally "in favor of more aggressive strategies that can protect public safety without sinking more and more state funds into prison," Gelb said.

Researchers point to a few clear trends as they analyze Colorado crime numbers and national recession trends:

• Criminals literally growing up are a major part of Colorado's shift to lower crime rates and fewer prisoners. Men ages 19 to 39 commit the largest number of crimes, and growth in that age group has slowed recently in Colorado.

• Drug courts, alternative sentencing and avoiding "technical" violations to parole or probation that can result in prison terms have all lowered recidivism rates and new sentences.

• Crime has not spiked alongside the economic crisis, countering previous recession trends that pushed up property crime, drug sales and even some violent crime.

Criminologist Rosenfeld said analysts are considering a handful of explanations: Methamphetamine use is down, and no other drug has taken up the crime-promoting role of crack in the late 1980s and early '90s; unusually high unemployment means more people are home protecting their houses and neighborhoods; smarter, more targeted policing methods; and stimulus money that propped up local policing budgets.

• Colorado legislation in 2009 increased "good time" credits for some prisoners, allowing more to leave 30 to 60 days before their mandatory release date. Supporters say the practice has proved to be a major incentive for behavior change in prisoners.

Corrections and budget officials are still assessing whether declining prisoner numbers are short blips or lasting trends, both in Colorado and nationwide. They worry criminals will find a new drug, that crime rates will flatten out or rise, that the recession will last long enough to make more people desperate.

Women's prison closed

Their budgets and planning, though, are already adjusting. Colorado's latest revisions will save $10.1 million from inmate reduction, $2.3 million on lower parole caseloads, and $6.1 million in prison medical care. Less demand made it possible to close a "boot camp" operation at Buena Vista, saving nearly another $1 million.

The female prison population has dropped much more quickly than men's, allowing Colorado to shutter the Colorado Women's Correctional Facility in Cañon City, Sanguinetti said. Colorado may need less space overall but will have to find new kinds of space for an aging prison population and a safer segregation of violent offenders.

To that end, next year's corrections budget includes an increase in staff and opening a recently completed high-security tower at Colorado State Penitentiary II.

"Until this last 18 months, the prison population had grown for decades," Sanguinetti said. "This is the first time it's occurred, and we understand it could reverse at any time."

Key to pushing the numbers down further is continuing expansion of drug-treatment alternatives, mental-health care, and proven policing strategies of the kind that have sharply reduced auto-theft rates, Ritter said. He also wants stronger job-training efforts during convicts' prison time and new strategies to help private employers hire former felons upon release.

While every governor in America is now asked whether he fears a "Willie Horton" moment — a parolee gone rogue that inflames public opinion — Ritter said he believes the public is now more receptive to prison alternatives backed by research and results.

In a democracy founded on concepts of liberty, Ritter said, "criminal-justice policy should always be open for discussion."

Michael Booth: 303-954-1686 or mbooth@denverpost.com