Though a federal review found private prisons are more dangerous than government-run prisons for both guards and inmates, the Trump administration indicated earlier this year that it will expand their use.

Private prison companies can be found at every level of government, housing 9 percent of the nation’s prisoners. They emerged in the 1980s, when the number of inmates was quickly outstripping capacity, and they have an outsize influence in certain states, including Arizona, Florida, Hawaii, Mississippi and New Mexico.

Despite hundreds of lawsuits, findings that private prisons save taxpayers little to no money, and evidence of repeated constitutional violations, the number of privately housed inmates has risen faster since 2000 than the overall number of prisoners. In 2016, the number rose by about 1.5 percent, according to Justice Department figures.

Last week, Frank Shaw, a warden for Management & Training, or MTC, at the East Mississippi Correctional Facility, was called to testify in a federal trial claiming that the prison routinely failed to shield inmates from beatings and left them so desperate for medical attention that they lit fires in their cells. Mr. Shaw had also been the warden in Arizona during the riot.

The trial concluded on Monday; the judge has yet to issue a decision.

Even states that have sworn off private prisons, or tried to cut back on their use, have found it difficult to extricate themselves. After the prisoners escaped in Arizona, the state tried to reduce the number of inmates held in that prison. But MTC claimed the state was violating its contract, which guaranteed a certain number of beds would be filled. Arizona had to pay the company $3 million. MTC still operates a facility in the state.