CHICAGO (CBS) — Having repeatedly called Cook County Jail the nation’s largest mental institution, Sheriff Tom Dart has tapped a clinical psychologist to run the facility.

Dr. Nneka Jones becomes the first mental health professional to run a jail in the U.S. She has been in charge of the mental health strategy at the jail, where 2,000 of the 9,000 inmates suffer from mental illness.

Jones said she sees part of her mission is working with Dart to make those inmates better citizens.

“As of today, we have almost a quarter of our inmate population identified as mentally ill. These individuals don’t belong in our custody,” she said. “We’ll work together to bring this to the national attention, and try to get these people out of the jail, and into a treatment facility.”

Jones said part of her role will be to act as a voice for those inmates.

“I believe, as the executive director, I’m at the forefront of the issue, and able to speak to the complexities that it brings; the environment in and of itself is not conducive to treating the mentally ill,” she said.

While the jail has brought overcrowding under control in general, Dart said that’s not the case in the psychiatric unit.

“We have some really rotten, horrible, bad, evil people in this jail; but for this larger group of people, thoughtful strategies have to be employed, and for any fool who wants to cling to this notion, ‘No, they shouldn’t have committed the crime that got them in here,’ you can’t argue with that type of moronic thinking,” he said.

The sheriff said a lot of the mentally ill inmates are charged with low-level offenses, and some get locked up intentionally for access to treatment they can’t get elsewhere.

“They shouldn’t be in here,” he said. “They did not commit a crime because they’re trying to hurt society, or hurt anybody at all; but when you take away all of the support systems for these folks, what thoughtful person wouldn’t think that these type of things will eventually occur? Of course they will.”

Jones said, in her roughly 10 years working at the jail, she has seen many people with severe mental illness who should be at a dedicated treatment center, not a jail.

“They’re coming in with psychotic disorders, severe mood disorders; and when you couple that with substance use – because they’re attempting to treat their illness, because it’s so difficult to access services in the community – we have our jobs cut out for us from the beginning to the end,” she said.