In 2013, I had the opportunity to spend a morning with a group of men convicted of murder at the Dixon Correctional Center. Dixon is the site of the Illinois prison system’s geriatric and medical unit, which houses people in varying degrees of physical decline.

One of those people was Joseph Hurst. Hurst has lived at Dixon since 2008, when he suffered a stroke that left him with a limp and collapsed his right hand. Hurst has spent 52 of his 76 ordered years in prison for the 1967 murder of Chicago police officer Herman Stallworth, who pulled him over for speeding near the corner of Cottage Grove Avenue and Marquette Road.

Now 78 years old, Hurst is almost certainly going to die in prison. Every time he comes up for parole, a busload of officers from the Chicago Police Memorial Foundation testifies against him. When it happened in 2013, Hurst insisted he was no longer a threat to society. Besides the complications related to his stroke, he also suffers from Parkinsonism and an enlarged prostate, which required his wearing a catheter. At one point during our talk, he lifted the cuff of his pants to show me a plastic bag bloated with urine.

“You can just see me sticking someone up and going down the street with a catheter,” he told me at the time.

I thought of Hurst when I read last week that the Prisoner Review Board had freed 80-year-old Chester Weger, the so-called Starved Rock Killer, who was convicted of murdering three women when he was a 20-year-old dishwasher at the state park. But I didn’t wonder why the state was freeing Weger so much as I wondered why it had imprisoned for so long — far past the point when he was likely to commit another crime, all the while subsidizing his food, shelter, and medical care.

The Illinois Department of Corrections classifies prisoners 50 or older as elderly. Elderly prisoners account for 20 percent of the state’s prison population, a proportion expected to grow to 30 percent by 2030. Due to hard living and the stress of confinement, prisoners are, on average, 10 to 15 years older physiologically than their contemporaries on the outside, according to a 2015 DOJ report.

Consequently, older prisoners suffer more medical problems. Housing an elderly prisoner costs $70,000 a year, compared to $27,000 for a younger offender, according to a 2012 study by the prison reform group John Howard Association. Releasing prisoners to their families, or to nursing homes, would shift their medical expenses to Medicare, saving the state millions of dollars a year.

Weger was eligible for parole because he committed his crime before 1978, when Illinois abolished discretionary parole in favor of truth in sentencing, which requires most violent offenders to serve 85 to 100 percent of their sentence. Today, a lifer can only be released if they receive clemency from the governor (or, as of June 1 of this year, if they were convicted before the age of 21 and have already served 10 years).

That 1978 change in law is a big reason the elderly prisoner population is growing so rapidly in Illinois. In 2017, a bill to create a supervised release program for elderly offenders was introduced in the General Assembly. It would have provided a chance at freedom for prisoners who are 55 years old and have served 20 years of their sentences. The bill never made it out of committee.

Aside from being expensive, some say imprisoning people into their 50s, 60s, and 70s doesn’t have a meaningful impact on public safety. That’s because many violent offenders age out of the behavior they were incarcerated for in the first place.

“Elderly people, especially those who have served significant prison sentences, almost never reoffend,” wrote reform activists Jennifer Soble and Bill Ryan in a Sun-Times editorial earlier this year. “In 2012, the state of Maryland released nearly 200 elderly people who had been convicted of murder and had served more than 20 years. Five years later, the group has a recidivism rate of 3% … in addition to being physically incapable of reoffending, many elderly inmates have spent decades on self-improvement, education and spiritual growth.”

In other words, murder is a young man’s game. According to the FBI, in 2016 the number of 20 to 24-year-olds convicted of murder (2,593) was greater than all of those over age 40. A study by U.S. Bureau of Justice Statistics found that 1.2 percent of those paroled on murder convictions were rearrested on a homicide charge within three years — the lowest recidivism rate of any crime. The 80-year-old Chester Weger about to leave prison is not the same 20-year-old who went in.

Joseph Hurst also insisted he wasn’t the same angry 24-year-old who’d killed a Chicago cop in the ’60s — and that even if he had been, he was no longer physically capable of acting on those impulses. There’s certainly a justification for not letting a cop killer out of prison early. But a kid who harms a rival gang member at 19 is not going back to that life at 49, or 59, or 69.

As Hurst told me in 2013: “The spirit of adventure that’s in a younger person’s not in an older person. The older person would tell him, ‘Son, I’ve been there, done that, don’t recommend it.’ Most [of us at Dixon] have been held beyond the benefit to society. You’ve got guys who can’t walk, guys who need help breathing. Sticking somebody up and running away is physically impossible.”