Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Date of Award

Spring 2017

Document Type


Degree Name

Master of Arts (MA)


Department of Graduate Psychology


Bernice Marcopulos

Dena Pastor

S. Jeanne Horst

Sharon Kelley


An estimated 60,000 forensic evaluations are conducted annually to determine if defendants meet the legal standard of competence to stand trial (CST); that is, if defendants have the ability to consult with their attorney, as well as if they have a rational and factual understanding of their charges. Estimated rates of feigning (i.e., faking or exaggerating of deficits or symptoms) in CST evaluations have ranged from 8% to 21%. Given this prevalence, it is necessary for forensic evaluators to have access to psychometrically sound instruments that can aid in the detection of feigning. Performance validity tests (PVTs) are designed to detect poor effort and response styles indicative of feigning. The Inventory of Legal Knowledge (ILK) is a PVT that was designed to detect feigned incompetence to stand trial. The current study examined the usefulness of the ILK in a psychiatric inpatient sample for the detection of feigning, with a focus on the instrument’s psychometric properties. Support was found for adequate reliability; however, evidence for construct and convergent validity were lacking. Several items that were long in length and had correct answers of “false” appeared to be difficult for the participants. Prior incarceration, having a forensic status, and a later onset of illness were related to higher ILK total scores. Future research recommendations, as well as concerns regarding the use of the ILK in inpatient settings were also addressed.

Available for download on Tuesday, April 17, 2018