Privately operated government prisons, which mostly detain migrants convicted of immigration offenses, are drastically more unsafe and punitive than other prisons in the federal system, a stinging investigation by the US Department of Justice's inspector general has found. Inmates at these 14 contract prisons, the only centers in the federal prison system that are privately operated, were nine times more likely to be placed on lockdown than inmates at other federal prisons and were frequently subjected to arbitrary solitary confinement. In two of the three contract prisons investigators routinely visited, new inmates were automatically placed in solitary confinement as a way of combating overcrowding. The review also found that contract prison inmates were more likely to complain about medical care, treatment by prison staff and about the quality of food. These facilities house around 22,000 individuals, mostly deemed "low risk", at an annual cost of $600m. They are operated by three private companies: Geo Group, Corrections Corporation of America (CCA), and Management and Training Corporation (MTC). These facilities were also more dangerous than others in the federal system. For example, the report found that inmate on inmate assaults were 28% higher in contract prisons. "This is the latest in a whole series of reports and investigations that have found very serious issues with Bureau of Prisons shadow systems of private prisons," said Carl Takei, a staff attorney with the ACLU.