This Sept. 2, 2015 file photo shows the the door to the cell at Hampton Roads Regional Jail in Portsmouth, Va., where 24-year-old Jamycheal Mitchell was found dead Aug. 19, 2015. (Bill Tiernan/ASSOCIATED PRESS)

BOTH MEN landed in jail on shoplifting charges. Both were ill, one vomiting blood, the other losing weight at a staggering rate. With their health in free fall, both needed urgent care. What they received was anything but urgent. It was neglect.

In the end, both Jamycheal Mitchell and Henry Stewart died at the Hampton Roads Regional Jail in Virginia. Jail staffers indifferent to their plight all but ignored symptoms that any layman would have recognized as alarming, at the least, and very possibly life-threatening.

Mr. Mitchell, who was 24, died in a cell spattered with his feces and puddled with his urine, having lost at least 35 pounds in the space of four months. Mr. Stewart, who was 60, alerted jail officials that he had blacked out twice in 24 hours; the response was a scolding by a nurse for refusing to take his seizure medication and “sitting on [a] walkway.” Two days later, he was dead.

Now the Justice Department’s Civil Rights Division has launched an investigation of conditions at the jail, 16 months after Mr. Mitchell’s death, in August 2015, and four months after Mr. Stewart’s, this past August. Lawyers and prosecutors will examine whether inmates with disabilities at the facility are provided with adequate services, as federal law requires — and as Mr. Mitchell and Mr. Stewart clearly were not.

One fair measure of a civilized society is the treatment it accords those it keeps locked away out of sight; that is particularly true in the case of the growing numbers of inmates across the country who are mentally ill. By that measure, the deaths of Mr. Mitchell and Mr. Stewart are a damning indictment.

Mr. Mitchell, whose crime was to shoplift two snacks and a soft drink from a 7-Eleven, worth $5.05, was physically healthy when he entered the jail in April 2015. He was also mentally ill. A judge ordered him transferred to a nearby state psychiatric hospital; the judge’s orders were ignored. In the meantime, jail officials and nurses seemed barely to notice, or care, as Mr. Mitchell’s weight plummeted and one of his legs swelled with edema. Hey, a top jail official said later, maybe he was flushing his food.

Mr. Mitchell’s death represented a systemic breakdown in Virginia: a jail ill-equipped to handle the swelling population of mentally ill inmates; a network of psychiatric hospitals, its bed count reduced to 1,300 from 6,000 in the past four decades, incapable of absorbing those needing urgent care; and communities, especially in poorer areas, lacking the funds, housing and professional services to treat those discharged from mental hospitals or diverted from jails.

Mindful of the mess, Gov. Terry McAuliffe (D) has proposed more than $30 million in new spending for mental illness and substance abuse. His budget would devote new funds to local mental-health providers, and to overcrowded psychiatric hospitals and private facilities, which handle the spillover. It’s a start, but only a start, in cleaning up a system that has become a disgrace.