A pre-sentence investigation (PSI) is an investigation into the background of a person after he or she has been found guilty of a crime, but occurs before sentencing. Generally, it is an investigation to determine a suitable sentence for the crime. Some information looked at during in a pre-sentence investigation includes past offenses, school records, military records, police records, driving records, and employment records. Any other information that can be used to establish a pattern of conduct typically is gathered. This information can have substantial impact on the sentencing of a defendant — a person with a perfect record with evidence of public service may receive less of a sentence for a driving under the influence (DUI) charge than a career criminal that was driving on a suspended license, even if nobody was hurt in either example.
Typically, a pre-sentence investigation includes an interview with the defendant and known associates to verify information found in official records. A person conducting the pre-sentence investigation is usually appointed by the court to gather the information and compile a report on the defendant's personal history. In order to ensure that a person does not spend an undetermined amount of time waiting for his or her sentence to be delivered, some jurisdictions may allow PSI investigators to begin a PSI before a person is found guilty based on the amount of evidence presented against the defendant. Compiling PSI-related documents is something that can be accomplished before a person is found guilty without hurting a defendant's case.
When the collection of data has been accomplished and the interviews conducted, the PSI investigator must interpret and analyze his or her data in order to form an opinion about how long a person's sentence should be. Part of the pre-sentence investigation report typically will include a justification for the investigator's sentencing opinion that may or may not be considered by the judge handing down the sentence. In most cases, the judge will follow the advice of the PSI investigator, but the judge will still retain the right to deviate from the investigator's opinion as allowed by law.
The intent of a pre-sentence investigation is to allow for discretionary sentencing so that those with the highest chance of being reformed may receive lower sentences. A PSI plays a crucial role in the criminal justice system because it ensures that the law is administered fairly. Courts use the PSI to determine sentences in proportion to crimes and in proportion to the past actions of the defendant.