The report is called Callous and Cruel: Use of Force against Inmates with Mental Disabilities in US Jails and Prisons. Here is an excerpt from the Summary:
Across the United States, staff working in jails and prisons have used unnecessary, excessive, and even malicious force on prisoners with mental disabilities such as schizophrenia and bipolar disorder.
Corrections officials at times needlessly and punitively deluge them with chemical sprays; shock them with electric stun devices; strap them to chairs and beds for days on end; break their jaws, noses, ribs; or leave them with lacerations, second degree burns, deep bruises, and damaged internal organs. The violence can traumatize already vulnerable men and women, aggravating their symptoms and making future mental health treatment more difficult. In some cases, including several documented in this report, the use of force has caused or contributed to prisoners’ deaths.
Prisons can be dangerous places, and staff are authorized to use force to protect safety and security. But under the US constitution and international human rights law, force against any prisoner (with mental disabilities or not) may be used only when—and to the extent—necessary as a last resort, and never as punishment.
As detailed in this report, staff at times have responded with violence when prisoners engage in behavior that is symptomatic of their mental health problems, even if it is minor and non-threatening misconduct such as urinating on the floor, using profane language, or banging on a cell door. They have used such force in the absence of any emergency, and without first making serious attempts to secure the inmate’s compliance through other means. Force is also used when there is an immediate security need to control the inmate, but the amount of force used is excessive to the need, or continues after the inmate has been brought under control. When used in these ways, force constitutes abuse that cannot be squared with the fundamental human rights prohibition against torture or other cruel, inhuman, or degrading treatment or punishment. Unwarranted force also reflects the failure of correctional authorities to accommodate the needs of persons with mental disabilities.