Sentencing guidelines are recommended ranges of punishment for criminal defendants after they have been convicted of a crime. Judges use official (generally legislative) guidelines in many jurisdictions in deciding the severity of punishment for a convicted defendant. Guidelines exist for jail time, monetary compensation, community service, and in some cases such as DUIs, even appropriate "classes" a convicted defendant must take. The federal government, several states, and some nations in Europe utilize sentencing guidelines.
The United States Sentencing Guidelines establish a base level offense number range for each crime, which amounts to a recommendation to the judge to sentence the defendant somewhere in the range depending on particular circumstances and degree of wrongdoing. Then the base level offense number is combined with the defendant's prior criminal history, if any, to calculate the total number of months in jail for the defendant. A 2- or 3-level decrease is usually available to defendants who accept a plea bargain and otherwise demonstrate acceptance of responsibility. The criminal history category that will apply is determined after the defendant has been convicted and the probation officer has prepared a presentence investigation report.
Examples of the base level offense range are bribery (seven to twelve), insider trading (eight), and blackmail (nine), money laundering (17 to 23) and serious drug trafficking charges (26 to 38). At lower levels each point corresponds to roughly a half-year in jail, and slightly longer in higher point ranges. For example, a base level offense of 38 for drug trafficking, with no prior criminal history (category I), corresponds to a range of 235 to 293 months in jail. There are 43 offense levels and 6 criminal history categories in the U.S. Sentencing Guidelines. Each 6-level increases roughly doubles the sentence. Sentencing ranges are, by law, required to be narrow, with the top of the range not exceeding the bottom of the range by more than 25% or 6 months, whichever is greater.
For drug offenses, the quantity of drugs (real and fake) determines the base level offense. A large amount of drugs, such as 50 kilograms, would be at the highest base offense level of 38, or about 20 years in jail. If someone died as a result of the drugs, then the prison sentence can be longer. Note that the defendant himself need not be caught with the drugs; if he is associated with a group that is accused of drug trafficking, then he will often be held responsible for the actions of any other member of the group as a conspiracy.
At the federal level, sentencing guidelines are prepared by the United States Sentencing Commission. These Guidelines were binding on judges until the U.S. Supreme Court decision in United States v. Booker caused them to become advisory.