2005 Federal Sentencing Guidelines
CHAPTER FIVE - PART K - DEPARTURES
1. SUBSTANTIAL ASSISTANCE TO AUTHORITIES 
§5K1.1. Substantial Assistance
    to Authorities (Policy Statement)
Upon motion of the government stating that the defendant has provided substantial
  assistance in the investigation or prosecution of another person who has committed
  an offense, the court may depart from the guidelines.
(a) The appropriate reduction shall be determined by the court for reasons
  stated that may include, but are not limited to, consideration of the following:
  (1) the court’s evaluation of the significance and usefulness of the
    defendant’s assistance, taking into consideration the government’s
    evaluation of the assistance rendered;
  (2) the truthfulness, completeness, and reliability of any information or
    testimony provided by the defendant;
  (3) the nature and extent of the defendant’s assistance;
  (4) any injury suffered, or any danger or risk of injury to the defendant
    or his family resulting from his assistance;
  (5) the timeliness of the defendant’s assistance.
Commentary
Application Notes:
1. Under circumstances set forth in 18 U.S.C. § 3553(e) and 28 U.S.C. § 994(n),
  as amended, substantial assistance in the investigation or prosecution of another
  person who has committed an offense may justify a sentence below a statutorily
  required minimum sentence.
2. The sentencing reduction for assistance to authorities shall be considered
  independently of any reduction for acceptance of responsibility. Substantial
  assistance is directed to the investigation and prosecution of criminal activities
  by persons other than the defendant, while acceptance of responsibility is
  directed to the defendant’s affirmative recognition of responsibility
  for his own conduct.
3. Substantial weight should be given to the government’s evaluation
  of the extent of the defendant’s assistance, particularly where the extent
  and value of the assistance are difficult to ascertain.
Background: A defendant’s
  assistance to authorities in the investigation of criminal activities has been
  recognized in practice and by statute as a mitigating sentencing factor. The
  nature, extent, and significance of assistance can involve a broad spectrum
  of conduct that must be evaluated by the court on an individual basis. Latitude
  is, therefore, afforded the sentencing judge to reduce a sentence based upon
  variable relevant factors, including those listed above. The sentencing judge
  must, however, state the reasons for reducing a sentence under this section.
  18 U.S.C. § 3553(c). The court may elect to provide its reasons to the
  defendant in camera and in
  writing under seal for the safety of the defendant or to avoid disclosure of
  an ongoing investigation.
Historical Note: Effective
  November 1, 1987. Amended effective November 1, 1989 (see Appendix
  C, amendment 290).