The US Department of Homeland Security in a 2015 annual report, "Immigration Enforcement Actions: 2015," available at dhs.gov, stated:

“ICE [Immigration and Customs Enforcement] officers base the determinations on risk to public safety, promoting compliance with removal proceedings or removal orders (i.e., reducing flight risk), and the availability and prioritization of resources. Options available to ICE include immigration detention, supervised alternatives to detention, release on bond, or release on the subject’s own recognizance, and may change at any point during the course of an alien’s time in the immigration enforcement system…

Section 238(b) of the INA [Immigration and Nationality Act] permits DHS [Department of Homeland Security] to administratively remove an alien if the alien has been convicted of an aggravated felony and did not have U.S. lawful permanent resident status at the time proceedings under this section commenced. Aliens subject to expedited removal, reinstatement of removal, or administrative removal generally are not entitled to proceedings before an immigration judge or to consideration for administrative relief unless the alien expresses fear of being persecuted or tortured upon return to his or her home country or the alien makes a claim to certain forms of legal status in the United States. The procedures for establishing the right for review by an immigration judge differ for each of these three removal processes.”

2015