(CN) – The 7th Circuit denied immunity to a doctor and nurse over the death of a schizophrenic prisoner whose diabetes went untreated after he was arrested for a misdemeanor.

Phillip Okoro had been jailed in Williamson County, Ill., for 69 days in late 2008 after he was arrested on suspicion of having committed a misdemeanor property crime.

While Okoro waited for a probable cause hearing, his family called the jail to inform it that Okoro suffered from Type I diabetes, which was controlled with careful monitoring of his blood sugar levels. Because Okoro had also been diagnosed with schizophrenia as teenager, he had difficulty monitoring and caring for his diabetes himself.

Okoro collapsed in his cell on Dec. 23, and was pronounced dead at the Heartland Regional Medical Center. He was 23 years old. A medical examiner found that the young man died of diabetic ketoacidosis, a buildup of acidic ketones in the bloodstream that occurs when the body runs out of insulin.

In an ensuing complaint, Jaclyn Currie claimed that her brother had been under the medical care of Dr. Jogendra Chhabra and nurse Marilyn Ann Reynolds, who were employees of Health Professionals Ltd., a private company under contract with the jail to provide medical services to the county's inmates.

Currie said the jail had mostly held Okoro in isolation, leaving jail employees and medical staff responsible for his care.

With adequate medical care, such as regular testing of his blood sugar levels and enough insulin to keep those levels steady, Okoro's death was "completely preventable," the complaint said.

Currie eventually settled with Williamson County and various jail officials, leaving Chhabra, Reynolds and Health Professionals as the sole remaining defendants.

A federal judge in East St. Louis refused to dismiss the claims against the medical contractors, and Chhabra and Reynolds appealed.

The Chicago-based federal appeals court affirmed Monday, refusing to distinguish between a jailer and medical professional "who unreasonably withholds insulin."

"This argument lacks support in law or logic," Judge Diane Wood wrote for a three-person panel. "'The state [has] a constitutional duty to provide adequate medical treatment to those in custody,' and constitutional claims may be brought against medical care providers, regardless of 'the precise terms of [their] employment,' when they 'voluntarily assume[] that obligation by contract.'"

The Fourth Amendment governs Currie's case because her brother's death happened while he was being held after a warrantless arrest, but before a judicial hearing to determine probable cause and before the state had established its interest in continued detention, according to the ruling. During this time, "greater solicitude to presumptively innocent arrestees is warranted," Wood wrote.

The standard for arrestees in this situation comes from the Fourth Amendment, not the Eighth or 14th Amendments, as Chhabra and Reynolds had asserted, the court found. Chhabra and Reynolds cannot assert qualified immunity as none of its previous rulings "hints at some special Fourth Amendment exemption for health care professionals," Wood wrote.

Chhabra and Reynolds also claimed that they should be entitled to qualified immunity because they did not know Okoro's inmate status, and therefore did not know whether "the Fourth Amendment, rather than some more forgiving constitutional provision, would govern this particular arrestee's medical care," Wood wrote.

Although qualified immunity can apply to some mistakes of fact, the court found that Chhabra and Reynolds' argument does not work in this case.

"It assumes that health care providers calibrate the level of medical care they provide to a jail inmate based on their assessment of the inmate's legal status, taking advantage of the right to be sloppy where the standard is lower," Wood wrote. "We sincerely hope that this is not how Chhabra, Reynolds, and Health Professionals, Ltd. go about caring for those in the state's custody."

If, however, Health Professionals and its employees "truly tailor their care (or lack thereof) in this fashion, then their failure to ascertain Okoro's correct status cannot be characterized as a 'reasonable' mistake, and their qualified immunity claim still fails," Wood wrote.