Allegheny County Jail

According to PA Rule 702, any sentence involving jailtime of a year or more needs to have a PSI (PreSentence Investigation) done.

The PSI is a factual history of the individual's criminal, residential, education, relative, and personal background to be recorded in an unbiased report. The PSI reprter will talk with the defendant first to get the needed history and ask what individuals they would like to contribute on record in the PSI, then try to contact those individuals to add to the record. The reporter will do a background check and include this information. The reporter will then talk to the victum(s) and any witnesses and include their staitements on the record. This is all prepared for the judge.

The defendant should have the opportunity to review the PSI and question and correct any information in it before proceeding. Then the judge will have you aknowledge that you understand the PSI and attest to its accuracy.
Arguments are made on both sides regarding the content of the trial, the outcome, and the information in the PSI, which all lend weight in the judge's decision on the sentence that should be imposed. This is it in a nutshell, but all sorts of little other things can creep in to add to the process, but mainly this is the format.