The New York Times reports on the US immigration detention process and the lack of transparency involved. 

From the NY Times: 

As the country debates stricter enforcement of immigration laws, thousands of people who are not American citizens are being locked up for days, months or years while the government decides whether to deport them. Some have no valid visa; some are legal residents, but have past criminal convictions; others are seeking asylum from persecution.

Death is a reality in any jail, and the medical neglect of inmates is a perennial issue. But far more than in the criminal justice system, immigration detainees and their families lack basic ways to get answers when things go wrong.

No government body is required to keep track of deaths and publicly report them. No independent inquiry is mandated. And often relatives who try to investigate the treatment of those who died say they are stymied by fear of immigration authorities, lack of access to lawyers, or sheer distance.

There are currently an estimated 12 million illegal migrants in the United States.