A specter is haunting America—and Halloween is over.

So says a recent report published by the Osborne Association and the Florence V. Burden Foundation on America’s aging prison population titled “The High Costs of Low Risk.” The study focuses on the increasing number of “low risk” elderly prisoners and the many ways they could complicate an already much-beleaguered criminal justice system. It’s just the latest piece of research to add to the ever-growing host of critiques lobbed at the U.S. prison system recently.

According to the report, America’s criminal justice system is finding itself bogged down by an expanding sector of older prisoners, and might soon be on the brink of collapsing under its own weight. As prisoners age and remain behind bars, they create some serious economic, moral, ethical, public health and safety concerns—all of which should be troubling for taxpayers.

Although both U.S. crime rates and its prison population are shrinking, older inmates are growing in numbers. From 1995 to 2010, the number of U.S. prison inmates aged 55 or older nearly quadrupled. Yes—quadrupled.

Why such a sharp spike in only 15 years? Prisoners incarcerated during the heyday of the nation’s fetish with harsh retribution, the 1980s and 1990s, lived in a period during which we saw the rise of controversial policies like mandatory minimum sentences and “three strikes” laws. According to the ACLU, the “warehousing of aging prisoners for low-level crimes and longer sentences is a nefarious outgrowth of the ‘tough on crime’ and ‘war on drugs’ policies of the 1980s and 1990s.” And as The Nation put it, only now is the full meaning of 25-to-life sinking in.

The report found that if this growth trend continues, by 2030, prisoners 55 and above are projected to compose about one-third of all incarcerated people in the U.S. That’s amounts to a staggering 4,400 percent increase within a fifty-year span. So what are some of the issues in tow that future generations might be saddled with?

For one, there’s the cost. Figures on annual spending for inmates ages 50 and older top $16 billion, which, with perspective, is more than the entire Department of Energy budget, or Department of Education funding for school improvements. On an individual level, it costs on average about twice as much to incarcerate a person over 50 ($68,270) as it does a younger, healthier cellmate ($34,135) annually. That’s largely due to factors like the unique needs of older people (increased health care, for example) that are compounded by the additional costs of correctional supervision. An officer assigned to guard an inmate undergoing health treatment outside of a prison, for example, costs around $2,000 per 24 hours. “It is clear that any long-term use of prisons as makeshift nursing homes is financially unsustainable,” the report notes.

It doesn’t help, either, that once in prison, inmates are subject to a higher prevalence of all sorts of communicable and chronic diseases like hepatitis, hypertension, cardiovascular disease, strokes, and Alzheimer’s. On top of that, elderly prisoners are more likely to risk injury, victimization, and ailing health than younger, healthier ones.

The fiscal concerns are no joke, especially given the rising number of elderly prisoners. But a pretty penny is not the only thing that taxpayers should loose sleep over. Apart from the host of diseases and limited health care older prisoners face, for example, incarceration tends to have a deteriorating effect on the body, causing them to physically age much faster than someone outside of prison. The stresses of prison life can put 10 to 15 years on, say, a 50-year-old.

Mental health issues are also a startlingly common trait among older prisoners. According to data from the Bureau of Justice Statistics, while roughly 40-60 percent of imprisoned people over 50 reported mental health problems, only one in three have access to treatment. Considering their prevalence and unique needs, this is a slice of the prison population that should fall on a network of specialized support mechanisms rather than face greater suffering for reasons out of their control—especially considering that research shows that it is age rather than time behind bars that guarantees the lowest recidivism.

This all comes at a time when funding the still sprawling prison system has gotten out of hand. Depressingly, spending on the average prisoner is much higher than on the average student in most states. And if that spending is only set to increase as more prisoners age, we will be faced with a potentially dire situation struggling to uphold a fiscally crippling apparatus housing a generation that it can’t take care of.