Witnesses in a federal criminal case may find themselves arrested, held for bail, and in some cases imprisoned until they are called upon to testify, 18 U.S.C. 3144. The same is true in most if not all of the states. Although subject to intermittent criticism, it has been so at least from the beginning of the Republic. The Supreme Court has never squarely considered the constitutionality of section 3144 or any of its predecessors, but it has observed in passing that, "[t]he duty to disclose knowledge of crime . . . is so vital that one known to be innocent may be detained in the absence of bail, as a material witness," Stein v. New York , 346 U.S. 156, 184 (1953). Even more telling may be an earlier remark from the Court to the effect that, "[t]he constitutionality of this [federal material witness] statute apparently has never been doubted," Barry v. United States ex rel. Cunningham , 279 U.S. 597, 617 (1929). In spite of the concerns of some that the authority can be used as a means to jail a suspect while authorities seek to discover probable cause sufficient to support a criminal accusation or as a preventive detention measure, the lower courts have denied that the federal material witness statute can be used as a substitute for a criminal arrest warrant. Particularly in the early stages of an investigation, however, an individual's proximity to a crime may make him both a legitimate witness and a legitimate suspect. Moreover, the Supreme Court recently held in Ashcroft v. al-Kidd that "an objectively reasonable arrest and detention of a material witness pursuant to a validly obtained warrant cannot be challenged as unconstitutional on the basis of allegations that the arresting authority had an improper motive." The Ashcroft five Justice majority, however, included Justice Kennedy who observed that the "Court's holding is limited to the arguments presented by the parties and leaves unresolved whether the Government's use of the Material Witness Statute in this case was lawful." The three other Justices, who shared that view and who had declined to join the majority opinion, separately declared that "[w]hether the Fourth Amendment permits the pretextual use of a material witness warrant for preventive detention of an individual whom the Government has no intention of using at trial is, in my view, a closer question than the majority's opinion suggests." It is clear, nevertheless, that the federal material witness statute is used with regularity and most often in the prosecution of immigration offenses involving material witnesses who are foreign nationals. Critics, however, contend that since September 11, 2001, seventy individuals, mostly Muslims, have been arrested and detained in abuse of the statute's authority. The federal material witness statute provides that: If it appears from an affidavit filed by a party that the testimony of a person is material in a criminal proceeding, and if it is shown that it may become impracticable to secure the presence of the person by subpoena, a judicial officer may order the arrest of the person and treat the person in accordance with the provisions of section 3142 of this title [relating to bail]. No material witness may be detained because of inability to comply with any condition of release if the testimony of such witness can adequately be secured by deposition, and if further detention is not necessary to prevent a failure of justice. Release of a material witness may be delayed for a reasonable period of time until the deposition of the witness can be taken pursuant to the Federal Rules of Criminal Procedure. 18 U.S.C. 3144. An arrest warrant for a witness with evidence material to a federal criminal proceeding may be issued by federal or state judges or magistrates. The statute applies to potential grand jury witnesses as well as to potential trial witnesses. Section 3144 on its face authorizes arrest at the behest of any party to a criminal proceeding. In the case of a criminal trial, both the government and the defendants may call upon the benefits of section 3144. Availability is a bit less clear in the case of grand jury proceedings. In a literal sense, there are no parties to a grand jury investigation other than the grand jury. Moreover, it seems unlikely that a suspect, even the target of a grand jury investigation, would be considered a "party" to a grand jury proceeding. The purpose of section 3144 is the preservation of evidence for criminal proceedings. Potential defendants, even if they are the targets of a grand jury investigation, have no right to present evidence to the grand jury. On the other hand, a federal prosecutor ordinarily arranges for the presentation of witnesses to the grand jury. It is therefore not surprising that the courts seem to assume without deciding that the government may claim the benefits of section 3144 in the case of grand jury witnesses. Issuance of a section 3144 arrest warrant requires affidavits establishing probable cause to believe (1) that the witness can provide material evidence, and (2) that it will be "impracticable" to secure the witness' attendance at the proceeding simply by subpoenaing him. Neither the statute nor the case law directly address the question of what constitutes "material" evidence for purposes of section 3144, but in other contexts the term is understood to mean that which has a "natural tendency to influence, or is capable of influencing, the decision of the decisionmaking body to which it was addressed." At the grand jury level, the government may establish probable cause to believe a witness can provide material evidence through the affidavit of a federal prosecutor or a federal investigator gathering evidence with an eye to its presentation to the grand jury. This may not prove a particularly demanding standard in some instances given the sweeping nature of the grand jury's power of inquiry. As to the second required probable cause showing, a party seeking a material witness arrest warrant must establish probable cause to believe that it will be impractical to rely upon a subpoena to secure the witness' appearance. The case law on point is sketchy, but it seems to indicate that impracticality may be shown by evidence of possible flight, or of an expressed refusal to cooperate, or of difficulty experienced in serving a subpoena upon a trial witness, or presumably by evidence that the witness is a foreign national who will have returned or been returned home by the time his testimony is required. Evidence that investigators have experienced difficulties serving a particular grand jury witness may not be enough to justify the issuance of an arrest warrant in all cases. With limited variations, federal bail laws apply to material witnesses arrested under section 3144. Arrested material witnesses are entitled to the assistance of counsel during bail proceedings and to the appointment of an attorney when they are unable to retain private counsel. The bail laws operate under an escalating system in which release is generally favored, then release with conditions or limitations is preferred, and finally as a last option detention is permitted. A defendant is released on his word (personal recognizance) or bond unless the court finds such assurances insufficient to guarantee his subsequent appearance or to ensure public or individual safety. A material witness need only satisfy the appearance standard. A material witness who is unable to do so is released under such conditions or limitations as the court finds adequate to ensure his later appearance to testify. If neither word nor bond nor conditions will suffice, the witness may be detained. The factors a court may consider in determining whether a material witness is likely to remain available include his deposition, character, health, and community ties. Section 3144 declares that "[n]o material witness may be detained because of inability to comply with any condition of release if the testimony of such witness can adequately be secured by deposition, and if further detention is not necessary to prevent a failure of justice." The corresponding federal deposition rule permits the witness, the government, or the defendant to request that a detained material witness' deposition be taken. A court enjoys only limited discretion to deny a detained witness' request. The Fifth Circuit has observed that, "Read together, Rule 15(a) and section 3144 provide a detained witness with a mechanism for securing his own release. He must file a written motion requesting that he be deposed. The motion must demonstrate that his testimony can adequately be secured by deposition, and that further detention is not necessary to prevent a failure of justice. Upon such showing, the district court must order his deposition and prompt release," Aguilar-Ayala v. Ruiz , 973 F.2d 411, 413 (5 th Cir. 1992). Other courts seem to agree. The "failure of justice" limitation comes into play when release of the witness following the taking of his deposition would ultimately deny a defendant the benefit of favorable material testimony in derogation of his right to compulsory process. It does not include the fact that a judicial officer will not be present at the taking of the deposition or that the witness is an illegal alien subject to prosecution. Unlike the request of a detained witness, a government or defendant's request that a witness' deposition be taken must show "exceptional circumstances" and that granting the request is "in the interest of justice," F.R.Crim.P. 15(a)(1). Nevertheless, the fact that a witness is being detained will often be weighed heavily regardless of who requests that depositions be taken. The Circuits appear to be divided over whether in compliance with a local standing order the court may authorize depositions to be taken sua sponte in order to release a detained material witness. In any event, whether any such depositions may be introduced in later criminal proceedings will depend upon whether the defendant's constitutional rights to confrontation and compulsory process have been accommodated. The government must periodically report to the court on the continuing justification for holding an incarcerated material witness. While a material witness is being held in custody he is entitled to the daily witness fees authorized for attendance at judicial proceedings. Upon his release, the court may also order that he be provided with transportation and subsistence to enable him to return to his place of arrest or residence. Should he fail to appear after he has been released from custody he will be subject to prosecution, an offense which may be punished more severely if his failure involves interstate or foreign travel to avoid testifying in a felony case. Witnesses at Congressional oversight hearings charged that the authority under 18 U.S.C. 3144 had been misused following September 11, 2001: [The authority has been used] to secure the indefinite incarceration of those [prosecutors] wanted to investigate as possible terrorist suspects. This allowed the government to . . . avoid the constitutional protections guaranteed to suspects, including probable cause to believe the individual committed a crime and time-limited detention. . . Witnesses were typically held round the clock in solitary confinement, subjected to the harsh and degrading high security conditions typically reserved for the most dangerous inmates accused or convicted of the most serious crimes. . . they were interrogated without counsel about their own alleged wrongdoing. . . . [A] large number of witnesses were never brought before a grand jury or court to testify. More tellingly, in repeated cases the government has now apologized for arresting and incarcerating the "wrong guy." The material witnesses were victims of the federal investigators and attorneys who were to[o] quick to jump to the wrong conclusions, relying on false, unreliable and irrelevant information. By evading the probable cause requirement for arrests of suspects, the government made numerous mistakes. At the same hearings the Justice Department pointed out that the material witness statute is a long-standing and generally applicable law and not a creation of the USA PATRIOT Act; that it operates under the supervision of the courts; that witnesses are afforded the assistance of counsel (appointed where necessary); and that witnesses are ordinarily released following their testimony. When the Committee reported H.R. 3199 following the hearings, section 12 of the bill would have amended section 1001 of the USA PATRIOT Act by directing periodic review of the exercise of the authority under section 3144. In its original form section 1001 instructs the Justice Department Inspector General to designate an official who is (1) to receive and review complaints of alleged Justice Department civil rights and civil liberties violations, (2) to widely advertise his availability to receive such complaints, and (3) to report to the House and Senate Judiciary Committees twice a year on implementation of that requirement, P.L. 107-56 , 115 Stat. 381 (2001). Section 12 would have amended section 1001 to impose additional responsibilities upon the Inspector General's designee , i.e. , (1) to "review detentions of persons under section 3144 of title 18, United States Code, including their length, conditions of access to counsel, frequency of access to counsel, offense at issue, and frequency of appearances before a grand jury," (2) to advertise his availability to receive information concerning such activity, and (3) to report twice a year on implementation to the Judiciary Committees on implementation of this requirement. Perhaps due to Administration opposition, the provision was dropped from H.R. 3199 prior to House passage. No similar provision could be found in H.R. 3199 ( S. 1389 ) as approved in the Senate, in the conference bill, H.Rept. 109-333 (2005), or the legislation ultimately enacted. S. 1739 , introduced by Senator Leahy, would have rewritten section 3144. In its recast form, section 3144 among other things would: establish a preference for postponing arrest until after a material witness has been served with a summons or subpoena and failed or refused to appear, unless the court finds by clear and convincing evidence that service is likely to result in flight or otherwise unlikely to secure the witness' attendance; make it clear that the provision applies to grand jury proceedings; explicitly permit arrest by officers who are not in physical possession of the warrant; require an initial judicial appearance without unnecessary delay in the district of the arrest or in an adjacent district if more expedient or if the warrant was issued there and the appearance occurs on the day of arrest; limit detention to 5 day increments for a maximum of 30 days (10 days in the case of grand jury witness); require the Attorney General to file an annual report to the Judiciary Committees on the number of material witness warrants sought, granted and denied within the year; the number of material witnesses arrested who were not deposed or did not appear before judicial proceedings; and the average number of days arrested material witnesses were detained. In lieu of the clear and convincing evidence standard in favor of release and the time limits on detention, the existing statute insists that "no material witness may be detained because of inability to comply with any condition of release if the testimony of such witness can adequately be secured by deposition, and if further detention is not necessary to prevent a failure of justice," 18 U.S.C. 3144. The proposed amendment had no comparable provision. In light of the 5-day limit on detention without further judicial approval, S. 1739 would have eliminated the reporting requirement now found in Rule 46(h)(2) of the Federal Rules of Criminal Procedure, i.e., "An attorney for the government must report biweekly to the court, listing each material witness held in custody for more than 10 days pending indictment, arraignment, or trial. For each material witness listed in the report, an attorney for the government must state why the witness should not be released with or without a deposition being taken under Rule 15(a)." The 109 th Congress adjourned without further action on these or any other legislative proposal to amend section 3144. No comparable proposals emerged in any subsequent Congress. Appendix A. 18 U.S.C. 3144 (text) If it appears from an affidavit filed by a party that the testimony of a person is material in a criminal proceeding, and if it is shown that it may become impracticable to secure the presence of the person by subpoena, a judicial officer may order the arrest of the person and treat the person in accordance with the provisions of section 3142 of this title. No material witness may be detained because of inability to comply with any condition of release if the testimony of such witness can adequately be secured by deposition, and if further detention is not necessary to prevent a failure of justice. Release of a material witness may be delayed for a reasonable period of time until the deposition of the witness can be taken pursuant to the Federal Rules of Criminal Procedure. Appendix B. Citations to State Material Witness Statutes

Summary:
This is an overview of the law under the federal material witness statute which authorizes the arrest of material witnesses, permits their release under essentially the same bail laws that apply to federal criminal defendants, but favors their release after their depositions have been taken. Legislative efforts in the 109th Congress to amend the provisions never fully developed. Witnesses at Congressional oversight hearings did alleged that the authority to arrest and hold material witnesses until their appearance at federal criminal proceedings (including grand jury proceedings) had been abused following September 11, 2001. Section 12 of the USA PATRIOT Act and Terrorism Prevention Reauthorization Act (H.R. 3199) as reported by the House Judiciary Committee would have required periodic reviews and reports on the use of the material witness statute. In the face of Administration opposition, however, the provision was dropped from the bill prior to House consideration. No similar proposal could be found in the version of H.R. 3199 (S. 1389) approved in the Senate or in the conference bill sent to the President. S. 1739, as introduced, would have rewritten the federal statute, setting detention time limits and raising evidentiary standards for arrest and detention among other things. The 109th Congress adjourned without further action on the material witness proposals, and subsequent Congresses passed without renewed legislative interest. The Supreme Court resolved on other grounds a case which might have been used as a vehicle to address constitutional challenges to the statute or use, Ashcroft v. al-Kidd, 131 S.Ct. 2074 (2011). Concurring opinions there, however, suggest that several members of the Court consider the matter an open question. A list of citations to comparable state statutes is appended. The report appeared in an earlier version as CRS Report RL33077, Arrest and Detention of Material Witnesses: Federal Law In Brief, by [author name scrubbed].