A wide variety of assessment instruments and procedures are used in forensic assessments. These may include three major categories: Forensic Assessment Instruments (FAIs), Forensically Relevant Instruments (FRIs), and Clinical Assessment Instruments (CAIs)
It depends on the type of crime. But for the general assessments can include norm-referenced psychological tests, informal tests and surveys, interview information, school or medical records, medical evaluation and observational data. Basically they conduct assessments to establish facts in court of law.