A Kentucky inmate is admitted to the hospital. Click here to see more of Tim Gruber’s great photos from inside a prison nursing unit.

Editor’s note: This article was supported by a MetLife Foundation Journalists in Aging Fellowship, a collaboration of New America Media and the Gerontological Society of America.

William “Lefty” Gilday had been in prison 40 years when the dementia began to set in. At 82, he was already suffering from advanced Parkinson’s disease and a host of other ailments, and his friends at MCI Shirley, a medium security prison in Massachusetts, tried to take care of him as best they could. Most of them were aging lifers like Lefty, facing the prospect of one day dying behind bars themselves, so they formed an ad hoc hospice team in their crowded ward. They bought special food from the commissary, heated it in an ancient microwave, and fed it to their friend. They helped him to the toilet and cleaned him up. Joe Labriola, 64, tried to see that Lefty got a little sunshine every day, wheeling his chair out into the yard and sitting with his arm around him to keep him from falling out.

But Lefty, who was serving life without parole for killing a police officer during a failed bank heist in 1970, slipped ever deeper into dementia. One day he threw an empty milk carton at a guard and was placed in a “medical bubble,” a kind of solitary confinement unit with a glass window that enables health care staffers to keep an eye on the prisoner. His friends were denied entrance, but Joe managed to slip in one day. He recalls an overpowering stench of piss and shit and a stack of unopened food containers—Lefty explained that he couldn’t open the tabs. Joe also noticed that the nurses in the adjoining observation room had blocked the glass with manila folders so they wouldn’t have to look at the old man.

Lefty had been popular among the prisoners, though. A minor-league ballplayer turned 1960s radical—his southpaw, not his politics, earned him the nickname—he was the subject of one of the most infamous manhunts in Massachusetts history. He had already been in and out of prison several times on robbery offenses when he fell in with a group of Brandeis University students who decided that stealing guns and money could help them foment a black revolution. They held up a bank in 1970, and when Boston police responded, guns drawn, a patrolman named Walter Schroeder was shot dead. Lefty claimed that he never meant to shoot the guy—that it was a warning round that ricocheted—but the jury didn’t buy it, and he was convicted of first-degree murder and sentenced to death. (The students got no more than seven years.)

In 1972, after the Supreme Court briefly banned capital punishment, Lefty became a lifer. Over time, he also became a jailhouse lawyer—a inmate paralegal who puts together legal cases for fellow prisoners—settling disputes and eventually gaining a rep as something of an elder statesman. When Lefty died last September, his friends were denied permission to hold a memorial service in the prison chapel, so they ended up holding it in a classroom. The service culminated in some 80 men sailing paper planes into the air as a tribute. “We loved the old man,” Joe Labriola wrote me in a letter.

Lefty Gilday was no ordinary inmate, but in one regard he typified a growing segment of America’s inmate population—geriatric prisoners. The United States leads the world in incarceration, with more than 2.2 million people in its prisons and jails, and the graying of this population is shaping up to be a crisis with moral, practical, and economic implications for cash-strapped governments. In recent years, a growing number of advocates—and even a handful of corrections officials and politicians—have dared to suggest that we consider setting some of these old-timers free.

As of 2010, state and federal prisons housed more than 26,000 inmates 65 and older and nearly five times that number 55 and up, according to a recent Human Rights Watch report. (Both numbers are significant, since long-term incarceration is said to add 10 years to a person’s physical age; in prison, 55 is old.) From 1995 to 2010, as America’s prison population grew 42 percent, the number of inmates over 55 grew at nearly seven times that rate. Today, roughly 1 in 12 state and federal prison inmates is 55 or older.

The trend is worsening. A new report from the American Civil Liberties Union estimates that, by 2030, the over-55 group will number more than 400,000—about a third of the overall prison population. (See chart.) “It’s huge,” says Bob Hood, the former warden of the mammoth federal correctional complex in Florence, Colorado. “We’re behind the eight-ball on this.”

From ACLU report: “At America’s Expense: The Mass Incarceration of the Elderly
The boom in geriatric prisoners is the inevitable result of legislation from the tough-on-crime 1980s and 1990s, which extended sentences and slashed parole opportunities, both dramatically so. According to a June report by the Pew Center on the States, drug offenders released in 2009 had spent 36 percent longer behind bars, on average, than those released in 1990. One in ten state prisoners nowadays is a lifer, and about the same proportion of federal prisoners over 50 are serving 30 to life. In short, more than 100,000 prisoners are currently destined to die in prison, and far more will remain there well into their 60s and 70s. Many of these men—as most of them are men—were never violent criminals, even in their youth. In Texas, for example, 65 percent of the older prisoners are in for nonviolent acts such as drug possession and property crimes.

Keeping thousands of old men locked away might make sense to die-hards seeking maximum retribution or politicians seeking political cover, but it has little effect on public safety. By age 50, people are far less likely to commit serious crimes. “Arrest rates drop to 2 percent,” explains Hood, the retired federal warden. “They are almost nil at the age of 65.” The arrest rate for 16-to-19-year-olds, by contrast, runs around 12 percent.

From ACLU report: “At America’s Expense: The Mass Incarceration of the ElderlyOnce released, therefore, the vast majority of the older prisoners never return. Data from New York state, for example, tracked 469 inmates who were originally sentenced for violent crimes and were later released as senior citizens—over a 13-year period, just 8 of those former inmates went back to prison, and only 1 went back for a violent offense. “The mass incarceration of the elderly is an example of our criminal justice system at its most heartless and its most irrational,” says David Fathi, director of the ACLU’s National Prison Project. “Most such prisoners are long past their crime-prone years and pose little to no public safety risk.”

Beyond any questions of efficacy or mercy lies the looming issue of the price tag. According to the ACLU, caring for aging prisoners costs American taxpayers some $16 billion annually. We shell out roughly $68,000 a year for each inmate over 50, twice what it costs to keep a younger person locked up. And the older the inmate, the greater the cost. “I’ve had inmates where a total cost of $100,000 a year is on the low side,” Hood says.

Even when you factor in post-incarceration expenses—for parole, housing, and public benefits such as health care—the ACLU projects that taxpayers save $66,000 a year, on average, for each inmate over 50 our prisons set free. “States are confronting the complex, expensive repercussions of their sentencing practices,” notes a 2010 report from the Vera Institute for Justice.

It’s not difficult to see why it costs so much. “The medical conditions that present themselves to long-term elderly inmates run anywhere from dialysis to cardiac treatment to dementia,” says Carl ToersBijns, who worked his way up from guard to deputy warden during his 30 years in the New Mexico and Arizona prison systems. “It is staff intensive,” he says. And the number of elderly inmates “is outgrowing the ability of corrections officers to handle and manage them—they’re not medically trained.”

Nor are prison facilities designed for people with mobility problems. Their assisted-living and hospice units are often chock full, Hood says, leaving the unlucky elders stuck in the general population without the services they need. Unless states start releasing them, Hood says, we will need to “retrofit every prison in America to put assisted living-units in it, wheelchair accessibility, handicapped toilets, grab bars—the whole nine yards.”