The Department of Justice made a landmark decision last week when it announced it would direct the Bureau of Prisons to let its contracts with private prison companies lapse .

But last weeks change in policy left the U.S. Marshals Service untouched, even though that agency is also under DOJ control and keeps nearly as many people locked in privatized jails as the Bureau of Prisons.

The U.S. Marshals Service is the countrys oldest federal law enforcement agency, acting under the authority of the federal courts. They provide courthouse security, run the Witness Protection Program and detain suspects facing federal criminal charges. When other federal agencies, like the Drug Enforcement Administration or the Border Patrol, arrest people for federal crimes, they hand the suspects off to the Marshals Service. Those convicted with short sentences often remain in the Marshals custody instead of being transferred to the Bureau of Prisons.

A Shifting Mission