2005 Federal Sentencing Guidelines
CHAPTER SIX - PART A - SENTENCING
PROCEDURES
§6A1.1. Presentence Report (Policy
Statement) 
(a) The probation officer must conduct a presentence investigation and submit
  a report to the court before it imposes sentence unless— 
  (1) 18 U.S.C. § 3593(c) or another statute requires otherwise; or
  (2) the court finds that the information in the record enables it to meaningfully
    exercise its sentencing authority under 18 U.S.C.
    § 3553, and the court explains its finding on the record. 
  Rule 32(c)(1)(A), Fed. R. Crim. P. 
(b) The defendant may not waive preparation of the presentence report. 
Commentary 
A thorough presentence investigation ordinarily is essential in determining
  the facts relevant to sentencing. Rule 32(c)(1)(A) permits the judge to dispense
  with a presentence report in certain limited circumstances, as when a specific
  statute requires or when the court finds sufficient information in the record
  to enable it to exercise its statutory sentencing authority meaningfully and
  explains its finding on the record. 
Historical Note: Effective
  November 1, 1987. Amended effective June 15, 1988 (see Appendix
  C, amendment 58); November 1, 1989 (see Appendix
  C, amendment 293); November 1, 1997 (see Appendix
  C, amendment 574); November 1, 2004 (see Appendix
  C, amendment 674).