COLUMBIA, Mo. -- When Verdia Miller celebrated her 75th birthday last month, she had been incarcerated for 35 years, five months and one day.

Under her sentence, she is ineligible for release until at least 2029, when she will be 87. She is serving a life sentence for capital murder.

That means taxpayers are shouldering the costs for her health care, which are mounting. Miller said she takes six different blood-pressure medications for hypertension. She treats her arthritis with over-the-counter pain medications and muscle rubs. Injuries from a fall on Christmas morning in 2015 require her to use a cane to walk long distances in the prison. X-rays and bone-density tests found signs of osteoporosis.

Miller simply is getting older, and her list of ailments likely will grow in the years to come. She is one of a rapidly increasing number of elderly inmates who will require more and more medical care. In Missouri, the number of people age 50 and older who are in prison is increasing at 11 times the rate of the prison population overall.

Prisoner advocates, prosecutors and state agencies have differing ideas of how to address the increase and its effect on the prison system. No comprehensive statewide policy exists. In short, there is no consensus on how long it makes sense to keep geriatric prisoners behind bars.

Verdia Miller stands with a cane she has to use at the Chillicothe Correctional Center on June 1 in Chillicothe, Missouri.Meg Vatterott ~ Missourian via AP

The oldest currently incarcerated person in Missouri is 92 years old, according to the Department of Corrections prisoner database. William Cone is serving consecutive sentences totaling 133 years in prison for 19 counts of sexual assault.

According to annual profiles of the prison population published by the Department of Corrections, Missouri's 50-and-older prison population has nearly doubled since 2005, compared to a less-than-10-percent increase in the total prison population during the same time.

About 6,000 of the more than 30,000 prisoners under Missouri's charge -- nearly 20 percent -- are older than 50. Of those 6,000, about three-fourths are in their 50s. About 1,300 are in their 60s, and about 300 are age 70 and older.

Part of the increase in the 50-plus prison population is because of new imprisonments and reimprisonments because of parole violations. But these circumstances account for only a small part of the increase.

Mostly, prisoners simply are getting older. The average jail sentence has increased across most crime classifications since 1993. According to a report from the Bureau of Justice Statistics, 60 percent of the over-55 state prison population nationwide aged into that category. In 2013, 40 percent of prisoners age 55 had served at least 10 years, a more than fourfold increase from 20 years prior.

As the number of elderly inmates increases, the number of inmates requiring expensive medical care also will increase.

A 2012 report from the American Civil Liberties Union states lack of access to healthy lifestyle options, added to the stress of day-to-day life in prison, accelerates the aging process, making prisoners 10 to 15 physiological years older than their chronological age.

So, most prisoners are considered elderly when they reach age 50. Additionally, prisoners nationwide have higher rates of mental illness, chronic medical conditions and infectious diseases than the general population, according to a 2016 survey of prison health care from the federal Centers for Disease Control and Prevention.

Care for these illnesses comes at a premium.

Missouri is one of 31 states nationwide to provide hospice care, care for chronic illnesses and long-term nursing-home care on-site in its prisons. Since 2012, the Department of Corrections has spent nearly $15,000 to make these care facilities compliant with the Americans with Disabilities Act, said David Owen, a spokesman for the department.

This medical care is provided by Corizon, a private-sector government contractor based in Brentwood, Tennessee, that provides health care to corrections facilities throughout the country.

Corizon is paid $12.59 per prisoner per day to cover medical and mental-health care services to Missouri prisoners. According to Corizon’s contract with the Department of Corrections, this per prisoner, per day rate is set to increase each year through June 30, 2021, when the contract expires. By 2021, the department will pay Corizon about 11 percent more than what is paid currently, at $14.17 per prisoner, per day. Owen attributed this increase to the increased cost of health care.

According to state government expenditure data on the online Missouri Accountability Portal, Corizon and its predecessor company, Correctional Medical Services Inc., have received more money — about $1.6 billion — from the Department of Corrections than any other vendors since 2000.

The contracted per diem rate is fixed and includes outpatient services, off-site medical care including surgeries, pharmaceutical services, mental-health care and all administrative overhead including personnel salaries, supplies and profit.

Prison life is physically demanding, according to Linda J. Redford, director of the Central Plains Geriatric Education Center at the University of Kansas Medical Center. But elderly prisoners face unique challenges.

In most prisons, walking long distances is a part of life, Redford said. As they age, many elderly prisoners find themselves unable to walk from one side of the yard to the other or up a flight of stairs to get medication.

They are also at increased risk of being victimized by other prisoners.

"The major thing is once you have an older prisoner who is in the general population, they could be targeted by the 'young punks' -- their terminology," Redford said. "They could be taken advantage of."

Elderly prisoners need allies and caretakers, people who can help and protect them. The logical choice for this is a cellmate, Redford said. But in prison, cellmates aren't supposed to have physical contact with one another, such as if, for example, someone needs help getting out of bed or up off the toilet. Cellmates of elderly prisoners who tried to help had good intentions but were untrained and feared getting in trouble for touching the people they were assisting.

When elderly prisoners no longer could care for themselves, they would be housed in the infirmary. Infirmary beds filled up, and sick prisoners were crowded out.

This was the impetus, Redford said, for a program within the Missouri Department of Corrections that trains volunteer prisoners to be "daily-living assistants." These assistants provide care much like a home health aide would in a non-prison setting. Redford worked with the Department of Corrections to develop this program.

For care beyond what a living assistant can provide, such as hospice or end-of-life care, prisoners first are sent to the prison infirmary, according to Missouri Department of Corrections spokesman David Owen.

If they require specialized long-term care, prisoners are sent to one of the six Enhanced Care Units in prisons around the state. These units started to come online about five years ago. In either situation, Owen said, prisoners are kept in the general population for as long as their illness will allow, under the supervision of medical staff.

The ACLU promotes voluntary compassionate release programs as a way to reduce costs associated with caring for aging prisoners. Missouri has a medical release policy, but it is strict.

According to the policy, a prisoner may be considered for medical parole when the prisoner has a terminal illness and is expected to die within six months, needs long-term nursing care or the prisoner's life will be shortened by staying in prison. Prisoners are not eligible for medical parole if they are sentenced to death, convicted of a crime that is ineligible for parole or if they have not served the minimum required time of their sentence.

Redford said medical parole is not a decision to be taken lightly. In some cases, prisoners are not emotionally or cognitively functional enough to be able to be released without proper support systems in place, she said.

"Medical parole will fail if there is not support from the community," Redford said.

Redford said many nursing facilities will not admit people with criminal records. Facilities that admit felons often are met with resistance from the community, and medically-paroled prisoners can have a hard time being placed in a care facility.

Redford also said elderly prisoners with long sentences can experience culture shock when they are released.

"Society has changed a lot in 20 years," she said. "For the older ones who have been in (prison) for years, it's another world out there."

With the proper care plan put in place, Redford said, along with a support system, she supports medical parole, but said it shouldn't be a blanket policy.

Legislators rejected two bills this year that would have made it easier for elderly prisoners to be granted parole.

House Bill 726 and Senate Bill 400 would have allowed certain offenders older than 65 a chance to present their case to the parole board. The Senate Committee on Legislative Research determined 44 prisoners would be eligible for a parole hearing immediately, and an additional 107 would become eligible by 2025. However, not everyone who is eligible for parole is granted parole. The potential savings to the state were estimated at just more than $175,000 by 2027.

Rep. Tom Hannegan, R-St. Charles, sponsored House Bill 726. He believes the cost savings estimates provided by the Senate's Legislative Research Committee are low and don't account for additional medical costs of elderly prisoners.

John Ammann, professor at Saint Louis University School of Law and legal clinic, works with the Community Coalition for Clemency. The coalition represents 14 women incarcerated in Missouri, including Miller, and advocates for clemency on their behalf. Ammann and his students have been working on legislative options to increase parole opportunities for elderly prisoners and testified in favor of House Bill 726 in March.

Ammann said a few of the prisoners who would qualify for an immediate parole hearing would be in their 80s.

If the bill had passed, Miller would have been eligible to request a hearing that could release her from prison. Miller was convicted for the 1978 murder of Larry Dean Smiddy in Jasper County. According to court records, Smiddy was shot by Eddie "Shyster" Jackson, a co-defendant, while both were inside a vehicle. Miller was outside of the car when Smiddy was shot. The court found Miller participated in the murder.

Callaway County Prosecutor Christopher Wilson said changing the law would have amounted to breaking a promise to victims. Wilson testified in opposition to House Bill 726 on behalf of the Missouri Association of Prosecuting Attorneys.

Wilson said the group of offenders to whom this bill would apply -- those sentenced to life without parole who are not sex offenders -- would almost entirely be those convicted of first-degree murder. Wilson said prosecutors often use the sentence of life without parole as leverage to avoid costly capital case litigation.

For someone facing a charge of capital murder, life without parole is a way to avoid the death penalty. For families of victims, they know that person will never be released from prison. If that policy is changed, Wilson said prosecutors would be less inclined to negotiate with defendants.

Hannegan said if families of victims feel strongly about the perpetrator being released from prison, they have the opportunity to testify at parole hearings to advocate in opposition to parole being granted.

Wilson said without the option of a plea deal that would waive the death penalty, there will be an increase in death-penalty litigation, which he speculated might offset the savings presented by paroling elderly inmates.

Hannegan said he will keep these concerns in mind when he revises the bill to reintroduce before the next legislative session.

Wilson said an alternative to parole of elderly prisoners is to seek executive clemency, which would amount to a suspension or commutation of an offender's sentence or outright pardon from the governor's office. This way, the release of prisoners could be determined on an individual basis rather than a blanket policy.

Possibly the most well-known instance of a Missouri governor granting clemency in recent years was for Faye Copeland. Before her sentence was commuted to life in prison, she was the oldest person in the nation on death row at age 69. Copeland was sentenced to death in 1991, with her husband Ray Copeland, for the murders of five drifters on their farm in rural Missouri.

Ray died in 1993 of natural causes before the death sentence could be carried out. Faye asserted she was a victim of domestic abuse and was merely doing what her husband demanded of her, and her sentence was commuted in 1999 to five life sentences without parole. Copeland suffered a stroke in August 2002 that left her paralyzed and unable to speak, and was granted clemency a few weeks later by then-Governor Bob Holden. She died about 15 months later in a nursing home in Chillicothe, Missouri.

Ammann has presented Miller's application for clemency to the governor's office in the past and will continue to work on her behalf. In the meantime, Miller has sought inspiration in the words of the one person with the power to grant her release with the stroke of a pen: Gov. Eric Greitens.

"I'm reading one of his books now about resilience," Miller said. "He's all about compassion, he's a humanitarian. I'm praying he'll help us."

Information from: Columbia Missourian, http://www.columbiamissourian.com