Advocates are requesting the U.S. Department of Justice to investigate the way North Carolina uses solitary confinement in prisons.
A letter from six organizations, including the state American Civil Liberties Union, claims more than 5,000 prisoners are deprived of fresh air, light and human contact on a given day, and that one-in-five prisoners should be receiving mental health care.
The letter references the death of Michael Kerr, a mentally ill inmate who died of dehydration last year after a month in solitude.
Chris Brook of the North Carolina ACLU said Kerr's death was the symptom of a larger problem.
"This has been an issue that has been known and understood at some level for almost a decade in our prison system, yet we continue to over-utilize solitary confinement, and place inmates often times suffering from mental illness in solitary confinement for very slight infractions, including the use of profanity," Brook said.
UNC law professor Deborah Weissman was lead author of a report last year that described long-term solitary confinement as an inhumane form of punishment.
"Once they land there, they are mistreated, they are abused and they are neglected, and their circumstances will only get worse," Weismann said.
Isolation can have a traumatic effect on inmates, exacerbating stress symptoms. Many inmates are also released directly from isolation to society.
Weissman and other advocates want the DOJ to pressure the state to offer comprehensive mental health care and discontinue prolonged use of solitary confinement.
State Prison Commissioner David Guice told state legislators in December the department needed an additional $20 million to hire enough staff to treat mentally ill inmates. The Senate budget proposes $6 million to cover hiring in the current fiscal year.