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42 U.S. Code § 1997a–1 - Subpoena authority

(a) Authority

The Attorney General, or at the direction of the Attorney General, any officer or employee of the Department of Justice may require by subpoena access to any institution that is the subject of an investigation under this subchapter and to any document, record, material, file, report, memorandum, policy, procedure, investigation, video or audio recording, or quality assurance report relating to any institution that is the subject of an investigation under this subchapter to determine whether there are conditions which deprive persons residing in or confined to the institution of any rights, privileges, or immunities secured or protected by the Constitution or laws of the United States.

(b) Issuance and enforcement of subpoenas
(1) IssuanceSubpoenas issued under this section—
(A)
shall bear the signature of the Attorney General or any officer or employee of the Department of Justice as designated by the Attorney General; and
(B)
shall be served by any person or class of persons designated by the Attorney General or a designated officer or employee for that purpose.
(2) Enforcement

In the case of contumacy or failure to obey a subpoena issued under this section, the United States district court for the judicial district in which the institution is located may issue an order requiring compliance. Any failure to obey the order of the court may be punished by the court as a contempt that [1] court.

(c) Protection of subpoenaed records and informationAny document, record, material, file, report, memorandum, policy, procedure, investigation, video or audio recording, or quality assurance report or other information obtained under a subpoena issued under this section—
(1)
may not be used for any purpose other than to protect the rights, privileges, or immunities secured or protected by the Constitution or laws of the United States of persons who reside, have resided, or will reside in an institution;
(2)
may not be transmitted by or within the Department of Justice for any purpose other than to protect the rights, privileges, or immunities secured or protected by the Constitution or laws of the United States of persons who reside, have resided, or will reside in an institution; and
(3)
shall be redacted, obscured, or otherwise altered if used in any publicly available manner so as to prevent the disclosure of any personally identifiable information.