Getting tough on crime at the Legislature has come at great cost to Minnesota's corrections system.

Over the past 25 years, the state's incarceration rate has soared by 150 percent, and Minnesota's prisons are bloated beyond capacity and burdened by runaway costs. The majority of that growth can be attributed to harsher penalties and other changes to the state's criminal code passed by state lawmakers.

"It's the accumulation of all the smaller decisions that have been made over time," said Kelly Mitchell, director of the University of Minnesota Law School's Robina Institute of Criminal Law and Criminal Justice. "It's not until you pull them all together that you see what the result is."

The effort to curb drunken driving is just one example of how what happens at the ­Capitol contributes to overcrowding in state prisons.

In 2001, Republican Rep. Rich Stanek — now Hennepin County sheriff — introduced a new weapon to battle chronic offenders: a felony charge carrying up to seven years. Then-Hennepin County Attorney Amy Klobuchar, a Democrat, was one of the bill's ardent supporters, calling it a top priority for state prosecutors.

Klobuchar acknowledged that cost estimates for the bill varied, but said the state could use creative options, like converted treatment facilities, to avoid deluging state prisons.

"Chronic DWI offenders don't need expensive maximum security incarceration," Klobuchar, now a U.S. senator, wrote in a letter to the Star Tribune. Reached this week, she and Stanek declined to comment.

DWI crackdown

The bill passed in 2002. Nearly a decade and a half later, the policy accounts for about 700 state inmates — the same number as those imprisoned for weapons violations, according to Department of Corrections data. That comes to about $23 million per year for incarceration alone, based on current annual costs of imprisonment in Minnesota.

Last year, DFL state Sen. Ron Latz, who co-chairs a committee designed to craft solutions to the overpopulation problem, pushed a bill amending gun laws to treat possession of ammunition the same as a firearm for felons. This law is projected to increase the prison population between 24 and 114 beds.

Latz acknowledged the bed impact, but said some laws appropriately carry longer sentences.

"It's not inconsistent," Latz said. "We take steps all the time that we think are in the best interest of public safety."

Latz said he will introduce his plan to address prison overpopulation in coming weeks.

In 1990, Minnesota prisons housed 3,182 inmates — about one-third of the present population, according to DOC data. By the end of the decade, that number had nearly doubled to just shy of 6,000.

Part of the rapid increase can be explained by a series of laws designed to crack down on drug users and dealers.

In 1991, possessing 25 grams of crack cocaine carried the same charge as 500 grams — or nearly a pound — of powder cocaine. A Minnesota Supreme Court decision ruled the disparate policies were unconstitutional because they disproportionately sent black people to prison, and the Legislature responded by making powder the same as crack.

Stiffer drug sentences

Over the next few years, lawmakers made methamphetamines and heroin the same as cocaine, lowering the minimum weight for high-level charges. For example, the minimum amount for first-degree sale — which carries a sentence of four to 40 years in prison — dropped to 10 grams, down from 50 grams, for heroin and meth.

These new laws collectively had a profound impact on prisons. From 1998 to 2005, the state's drug-crime inmate population more than tripled from 700 to nearly 2,200.

Other major legislation increased sentences for crimes related to stalking, harassment and domestic abuse. One law, passed in 2005, hardened penalties for domestic abuse by strangulation. A couple of years later, legislators created a felony-level charge for violators of a domestic abuse no-contact order — similar to a restraining order — which can carry up to five years in prison.

In response, the prison population for these offenders has increased from 51 inmates to 599 since 2000, a 12-fold spike in 15 years, according to DOC data.

Another major feeder to prisons has been gun legislation. In 1998, the Legislature increased the minimum sentence for a violent felon caught with a firearm from 18 months to five years, which created a need for about 400 more beds, according to estimates from the Minnesota Sentencing Guidelines Commission.

After a new felony or longer sentence passes the Legislature, it creates a ripple effect in the criminal justice system.

Minnesota doesn't have a parole board. Instead, inmates serve two-thirds of their sentences in prison and the last leg on supervised release. If offenders violate the terms of their release, they often go back to prison.

A longer prison sentence means a longer term on supervised release, which in turn creates more time for an offender to violate and return to prison.

Grant Duwe, director of research for DOC, points to trends in sex crimes as an example of how this ripple effect can increase the prison population. In the mid-2000s, lawmakers passed several policies creating longer sentences for those convicted of criminal sexual misconduct. In turn, from 1991 to 2015, the population of inmates imprisoned for these crimes jumped from 682 to about 1,700.

It's not that sex crimes went up in that time. "That number has remained remarkably steady since the early 1990s," Duwe said. Rather, the spike is linked to more offenders coming back to prison for violating their release.

This aspect of Minnesota's corrections system has generated some debate. Last year, release violators accounted for about one-third of prison admissions, DOC data show. Another 28 percent were probation violators. Some of these people are convicted of new crimes, but others only violate the technical terms of their release, such as failing or refusing a drug test.

"I think that that's where we really need to do the hard work in Minnesota," said Mitchell, who is also part of a legislative task force on prison overpopulation. "What is causing offenders to fail on probation and fail supervised release?"

Jail space running out

In March 2013, with no more room in its prisons, the state began contracting with county jails to house overflow inmates. It's unclear how long this temporary solution will last.

Currently, there are about 1,440 vacant beds in all Minnesota jails, according to DOC data. But jails won't accept high-risk offenders — or offenders classified above low or medium security — and since the prison population is fluid, DOC administrators don't know how many inmates meet these criteria.

"We've got a short-term crunch right now," Latz said. "We're just about at capacity with the county jail systems."

Legislators have been discussing potential long-term solutions to the overpopulation but have so far been split on what path to take. Gov. Mark Dayton recently dropped a $141 million proposal from his bonding bill that would have expanded the DOC's Rush City facility, saying he'd rather find ways to reduce the prison population than spend money on major building projects. Others believe the answer lies in the state leasing Prairie Correctional Facility, a private prison in Swift County shut down in 2010.

In the meantime, the prison population is set to keep rising, and the state will continue to rely on the jails, which DOC officials and advocates for prison reform agree is not an ideal permanent fix.

"Clearly that's not the best course of action," said Josh Esmay, director of public policy and advocacy for the Council on Crime and Justice. "The folks who get stuck in the county jails get a worse experience. They have less access to constructive activities and programming. They're just kind of sitting there with nothing to do."

With jails only accepting medium- and low-risk inmates from prisons, who would then lose those privileges, Esmay said, "it almost creates a penalty for good behavior."

Andy Mannix • 612-673-4036