Picture a facility many of whose occupants are obviously frail, ill or disabled. Most have sparse or graying hair. A number lean upon canes or walkers; others navigate by means of wheelchairs. Some cannot even leave their beds or eat and drink without assistance. Surely this must be a senior citizens’ or nursing home. But if so, why are the denizens all male and dressed in identical colored jumpsuits? The answer is that you are looking at a prison — and not a unique one.

According to two recent reports by the American Civil Liberties Union and Human Rights Watch, the population of elderly inmates has risen dramatically since 1980. ACLU, At America’s Expense: The Mass Incarceration of the Elderly; Human Rights Watch, Old Behind Bars: The Aging Prison Population in the United States. Currently almost 250,000 prisoners, about 16 percent of imprisoned convicts, are above 50; they can be considered “old.” (Given the lack of decent health care before and after incarceration as well as the stresses of life in prison, their greater physiological age makes 50 an appropriate marker.) By 2030, experts predict, the proportion 55 and older will grow to one-third — an escalation since 1981 of 4,400 percent.

What has happened? To quote from the ACLU study, we are not witnessing an “ ’elderly crime wave.’ ” Rather the graying of our penal institutions is just that. It reflects the aging of inmates who committed crimes in their youth and who, during the past three decades, have increasingly received terms of at least 20 years.

This phenomenon results directly from the draconian sentencing laws — mandatory minimums, “three-strikes-and-you’re-out” provisions, parole restrictions or abolition — enacted since the mid-1970s. Many individuals imprisoned under these new regimes will never experience freedom again: From 1984 to 2002, the number of prisoners in this country serving life sentences more than quadrupled.

Whatever one thinks of the general wisdom of the “tough-on-crime” approach, it clearly has had a negative impact on prison demographics and management. Institutional medical care is at best marginal even for the average inmate. Thus, penitentiaries plainly cannot serve as hospitals, nursing homes or hospices for their elderly infirm or dying residents, whose burgeoning ranks have been swollen by our sentencing policies.

In order to furnish them with adequate treatment, the authorities must resort to care outside prison walls. Not only the specialized therapies themselves but also security and transportation impose very substantial costs on already strained government budgets. If officials seek to avoid such expenses by simply turning a blind eye to their charges’ needs, they risk incurring lawsuits under the Eighth Amendment — not to speak of defaulting on their moral and professional obligations.

The best way to deal with the problem posed by geriatric inmates is to reduce their numbers dramatically. If we cannot, at least in the short term, amend prevailing sentencing laws, we can find ways to address their likely unintended consequence: the vast population of elderly, chronically ill prisoners draining the system’s straitened finances. The most direct means to do so is to release those who present no realistic threat to society.

THE ‘AGING OUT’ PHENOMENON

Research has convincingly shown that criminals “age out” of crime: Out of all arrests nationwide, arrest rates fall to slightly more than 2 percent at age 50, nearly 0 percent at age 65. Further, because many of the long-term incarcerated are predicate felons confined for low-level, frequently nonviolent offenses, discharging at least those inmates into the community would pose little risk. In addition, it is hard to see how paroling prisoners who suffer from disabling medical conditions can harm anyone.

On account of the disproportionate expense of maintaining the aging behind bars, such a policy would be cost-effective as well as compassionate. Even taking into account state and federal liability for public benefits an elderly, sick parolee might incur (e.g., for public assistance or health care), the ACLU report calculates that his release would pare at least $28,362 a year from the budget; savings might even run to more than $68,000 annually per inmate.

According to a 2010 study by the Vera Institute of Justice (“It’s About Time”), 15 states and the District of Columbia have statutes authorizing various types of geriatric release. All states should enact such laws. But by itself reform on the books will accomplish little. Inflexible criteria excluding those who have been convicted of certain crimes or have not served a certain number of years, combined with overly burdensome procedures, have gutted most existing programs.

Lawmakers doubtless fear political repercussions from real reform: One Willie Horton furlough-gone-wrong can destroy a legislator’s career. Responsible officials should lay the foundation for effective change through public education about the relative risks and rewards of adopting more generous discharge policies for the sick and elderly who simply do not belong in prison.

Vivian Berger is professor emerita at Columbia Law School.