The Child Protection Act of 2012, P.L. 112-206 ( H.R. 6063 ) authorizes the Marshals Service to use administrative subpoenas to track unregistered sex offenders. Administrative Subpoenas Generally

Administrative agencies have long held the power to issue subpoenas and subpoenas duces tecum in aid of the agencies' adjudicative and investigative functions. In an early examination of the questions, the Supreme Court held that the Fourth Amendment did not preclude enforcement of an administrative subpoena issued by the Wage and Hour Administration notwithstanding the want of probable cause. The Justice Department reports that the Inspector General's administrative subpoena authority is mainly used in criminal investigations, and the courts have held that the act gives the Inspectors General both civil and criminal investigative authority and subpoena powers coextensive with that authority.
Proponents refer to administrative subpoenas as a quick, efficient and relatively nonintrusive law enforcement tool. Opponents express concern that they pose a threat of unchecked invasions of privacy and evasions of the Fourth Amendment warrant and probable cause requirements.
The courts have determined that, as long as they are not executed in a manner reminiscent of a warrant, administrative subpoenas issued in aid of a criminal investigation must be judicially enforced if they satisfy statutory requirements and are not unreasonable by Fourth Amendment standards.
The Child Protection Act of 2012, P.L. 112-206 (H.R. 6063) authorized the United States Marshals Service to issue administrative subpoenas in aid of tracking unregistered sex offenders.
This report is an abridged version—without footnotes, appendixes, quotation marks, and most citations to authority—of CRS Report RL33321, Administrative Subpoenas in Criminal Investigations: A Brief Legal Analysis, by [author name scrubbed].