2005 Federal Sentencing Guidelines
CHAPTER SIX - PART A - SENTENCING PROCEDURES
§6A1.3. Resolution of Disputed
Factors (Policy Statement) 
(a) When any factor important to the sentencing determination is reasonably
  in dispute, the parties shall be given an adequate opportunity to present information
  to the court regarding that factor. In resolving any dispute concerning a factor
  important to the sentencing determination, the court may consider relevant
  information without regard to its admissibility under the rules of evidence
  applicable at trial, provided that the information has sufficient indicia of
  reliability to support its probable accuracy. 
(b) The court shall resolve disputed sentencing factors at a sentencing hearing
  in accordance with Rule 32(i), Fed. R. Crim. P. 
Commentary 
Although lengthy sentencing hearings seldom should be necessary, disputes
  about sentencing factors must be resolved with care. When a dispute exists
  about any factor important to the sentencing determination, the court must
  ensure that the parties have an adequate opportunity to present relevant information.
  Written statements of counsel or affidavits of witnesses may be adequate under
  many circumstances. See, e.g., United
  States v. Ibanez, 924 F.2d 427 (2d Cir. 1991). An evidentiary hearing
  may sometimes be the only reliable way to resolve disputed issues. See, e.g., United
  States v. Jimenez Martinez, 83 F.3d 488, 494-95 (1st Cir. 1996) (finding
  error in district court’s denial of defendant’s motion for evidentiary
  hearing given questionable reliability of affidavit on which the district court
  relied at sentencing); United States
  v. Roberts, 14 F.3d 502, 521(10th Cir. 1993) (remanding because district
  court did not hold evidentiary hearing to address defendants’ objections
  to drug quantity determination or make requisite findings of fact regarding
  drug quantity); see also, United
  States v. Fatico, 603 F.2d 1053, 1057 n.9 (2d Cir. 1979), cert. denied,
  444 U.S. 1073 (1980). The sentencing court must determine the appropriate procedure
  in light of the nature of the dispute, its relevance to the sentencing determination,
  and applicable case law. 
In determining the relevant facts, sentencing judges are not restricted to
  information that would be admissible at trial. See 18
  U.S.C. § 3661; see also United
  States v. Watts, 519 U.S. 148, 154 (1997) (holding that lower evidentiary
  standard at sentencing permits sentencing court’s consideration of acquitted
  conduct); Witte v. United States,
  515 U.S. 389, 399-401 (1995) (noting that sentencing courts have traditionally
  considered wide range of information without the procedural protections of
  a criminal trial, including information concerning criminal conduct that may
  be the subject of a subsequent prosecution); Nichols
  v. United States, 511 U.S. 738, 747-48 (1994) (noting that district
  courts have traditionally considered defendant’s prior criminal conduct
  even when the conduct did not result in a conviction). Any information may
  be considered, so long as it has sufficient indicia of reliability to support
  its probable accuracy. Watts,
  519 U.S. at 157; Nichols, 511
  U.S. at 748; United States v. Zuleta-Alvarez,
  922 F.2d 33 (1st Cir. 1990), cert. denied,
  500 U.S. 927 (1991); United States
  v. Beaulieu, 893 F.2d 1177 (10th Cir.), cert. denied,
  497 U.S. 1038 (1990). Reliable hearsay evidence may be considered. United
  States v. Petty, 982 F.2d 1365 (9th Cir. 1993), cert. denied,
  510 U.S. 1040 (1994); United States
  v. Sciarrino, 884 F.2d 95 (3d Cir.), cert. denied,
  493 U.S. 997 (1989). Out-of-court declarations by an unidentified informant
  may be considered where there is good cause for the non-disclosure of the informant’s
  identity and there is sufficient corroboration by other means. United
  States v. Rogers, 1 F.3d 341 (5th Cir. 1993); see also United
  States v. Young, 981 F.2d 180 (5th Cir.), cert. denied,
  508 U.S. 980 (1993); United States v.
  Fatico, 579 F.2d 707, 713 (2d Cir. 1978), cert. denied,
  444 U.S. 1073 (1980). Unreliable allegations shall not be considered. United
  States v. Ortiz, 993 F.2d 204 (10th Cir. 1993). 
The Commission believes that use of a preponderance of the evidence standard
  is appropriate to meet due process requirements and policy concerns in resolving
  disputes regarding application of the guidelines to the facts of a case. 
Historical Note: Effective
  November 1, 1987. Amended effective November 1, 1989 (see Appendix
  C, amendment 294); November 1, 1991 (see Appendix
  C, amendment 387); November 1, 1997 (see Appendix
  C, amendment 574); November 1, 1998 (see Appendix
  C, amendment 586); November 1, 2004 (see Appendix
  C, amendment 674).