We aimed to explore the use of instruments in 500 Norwegian reports of forensic evaluations of criminal responsibility from 2009-2018, in cases with serious violent crimes; specifically, whether this use was associated with diagnostic and forensic conclusions.

The first author coded data from all reports. Two co-authors then coded a random sample of 50 reports, for inter-rater reliability. We present descriptive measures and associations between use of instruments and diagnostic and forensic conclusions.

Instruments were used in 50.0% of reports. The Wechler’s Adult Intelligence Scale (WAIS), Historical Clinical Risk-20 (HCR-20), and the Structured Clinical Interview for DSM disorders (SCID I), were used in 15.8, 13.8, and 9.0% of reports, respectively. The use of instruments increased over the years. Instruments were more often used by teams with both psychologists and psychiatrists. The use of instruments was strongly associated with both diagnostic and forensic conclusions.