What legislative document provides guidelines on the weight given to mitigating factors in sentencing decisions?

The Crimes (Sentencing Procedure) Act 1999 is the correct choice because it specifically outlines the framework and guidelines for sentencing in New South Wales. This legislative document includes provisions that detail how courts should consider various factors, including mitigating factors that may influence the severity of a sentence imposed on an offender. Mitigating factors can include aspects such as the offender's background, personal circumstances, or any circumstances that may lessen the degree of responsibility for the crime committed.

This Act serves to ensure a structured approach to sentencing, allowing for consistency and fairness in the judicial process. It also emphasizes the judicial discretion exercised by judges when weighing these factors. Other options, such as the Civil Procedure Act 2005 and the Criminal Code Act 1995, focus on different areas of law—civil procedures and substantive criminal offenses, respectively—while the Jury Act 1997 pertains to the operation and management of juries in trials. Therefore, none of these alternatives provide relevant guidelines on the consideration of mitigating factors in sentencing decisions, making the Crimes (Sentencing Procedure) Act 1999 the appropriate legislative document for this context.