The number of US state and federal prisoners age 55 or older nearly quadrupled between 1995 and 2010, growing by 282 percent, while total number of prisoners grew by less than half, 42 percent.

Back to the Denver Post article:

Colorado's total prison population more than doubled from 1991 to 2009, but the number of inmates age 50 or older increased 720 percent, according to "Old Behind Bars," a 2012 study by Human Rights Watch. Nationwide, the number of people in prison who are 65 or older increased 67 percent in only three years to 26,200 in 2010.

...Between 1994 and 2012, annual Colorado prison medical costs boomed to $77.6 million from $15.9 million, according to DOC records.

It is far less expensive to run a hospice than pay for chemotherapy and radiation. But DOC says the program was created because "it's the humane thing to do."

One of the prison's doctors, Dr. John Buglewicz, says:

What I'm seeing lately is a number of elderly inmates who are demented. We're going to see more cancers," he said. "It's going to end up costing huge amounts of money."

Elderly inmates don't pose a threat to society, Buglewicz said. Many have had strokes. Territorial at any given time has between 30 and 50 prisoners scooting around in wheelchairs. "They don't even know why they are here," he said.

While the Department of Corrections has an early compassionate release policy, many nursing homes and hospitals won't accept inmates.

"It was the humane thing to do," Tessier said.

In June, 2012, the ACLU released a report "At America's Expense: The Mass Incarceration of the Elderly."

Our extreme sentencing policies and a growing number of life sentences have effectively turned many of our correctional facilities into veritable nursing homes — and taxpayers are paying for it.

This increasing 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. Given the nation’s current overincarceration epidemic and persistent economic crisis, lawmakers should consider implementing parole reforms to release those elderly prisoners who no longer pose sufficient safety threats to justify their continued incarceration.

The ACLU says states would save $66,000. per year for each released elderly inmate. The full report is available here.