DOJ: Private prisons are more dangerous than government prisons - for inmates and guards
These "contract prisons" were first developed as a solution to alleviate overcrowding in public Bureau of Prisons (BOP) facilities - they typically hold adult male inmates who are undocumented immigrants and are nearing the end of their sentences.
As of December 2015, contract prisons held around 22,660 federal inmates, or roughly 12% of the BOP's total prison population.
The report compared data from 14 contract prisons to 14 BOP prisons to measure incidents per capita in eight categories: contraband, reports of incidents, lockdowns, inmate discipline, telephone monitoring, selected grievances, urinalysis drug testing, and sexual misconduct.
In all but two categories - drug tests and sexual misconduct - contract prisons had a higher number of incidents per capita.
Contract prisons also confiscated eight times as many contraband cell phones as in BOP prisons, and had higher rates of physical assaults, both by inmates on other inmates and inmates on staff.
The Department of Justice also made individual visits to three contract prisons, all of which had been cited for at least one safety or security deficiency.
In two of those prisons, inmates were being housed in units normally reserved for disciplinary segregation - when they hadn't done anything to justify it - because beds were not available in normal housing. The prisons also did not ensure that inmates were receiving adequate medical services.
These problems were subsequently corrected, but the DOJ concluded that more oversight was still necessary "to ensure that federal inmates' rights and needs are not placed at risk when they are housed in contract prisons."
Notably, however, inmates in contract prisons filed fewer grievances than inmates in BOP facilities - 72.6 per month in private prisons compared to 121.5 in public prisons, according to the report.
The DOJ made a number of recommendations for the BOP, encouraging it to "evaluate why contract prisons had more safety and security incidents in these categories and identify possible approaches for corrective action."