Explain how mental health is a challenge for the criminal justice system

In a report from the Council of State Governments Justice Center using a sample of local jails, 16.9 percent of the incarcerated adults had a mental illness. This is a much higher percentage than is in the regular population. After the de-institutionalization of state hospitals, state prisons have have seen an increase in the percentage and number of mental health inmates. Therefore, mental health presents a real challenge for the criminal justice system.
Law enforcement officials throughout the country are partnering with local mental health advocates and mental health service providers more and more in an effort to make it easier for law enforcement to enable people with mental illnesses to receive much needed services. Studies also report that 40 percent of individuals with serious mental illnesses have been in jail or prison at some time in their lives.
In an interview with retired officer Mr. Dennis Jones from United States Federal Penitentiary at Marion, Illinois, the highest level penitentiary before the super-max penitentiary in Colorado was constructed, the following information was provided on the challenges of mental health in a prison setting:
Mental health has long been a challenge for the criminal justice system. While there are psychological services that are available and at least one psychiatrist is on call at the prison, there is normally no mental hospital available. Therefore, medication is given in order to control inmates who have severe psychological problems; however, these inmates must be carefully monitored to ensure that they actually take their medication. Even so, sometimes there are inmates whose mental conditions become so elevated that they cannot remain in the institution. They are then sent to a psychiatric hospital.
In addition, many of the other prison inmates are frightened by those prisoners who have mental health issues, especially if they talk to themselves, hallucinate, or self-mutilate. When these other inmates are frightened and unnerved by the erratic behavior of mentally unstable inmates, there is the potential for dangerous conflict between inmates.
Still another problem for inmates with mental health challenges arises with their release, because they are often uninsured in the months after their release. This, too, is a time during which the inmates are susceptible to having an increased risk of medical problems and even death, but they are without insurance to pay for medication and treatment.

If former prisoners seek psychiatric help and are not covered by Medicaid or other financial assistance programs, they will end up in the emergency room. Most emergency rooms are not equipped to handle people who are mentally ill. In addition, most of the mentally ill have a co-occurring disorder that needs treatment. 

If these former prisoners end up in the emergency room, the taxpayer must absorb the costs that these people incur.
https://csgjusticecenter.org/reentry/issue-areas/mental-health/

https://www.mhanational.org/issues/criminal-justice