Forensic Psychology

Please help us improve this resource! Complete our 60-second survey. We want to hear from you each time you visit, and it’s always anonymous.


Language Services Section, Special Programs Unit, Programs and Procedures Division, Office of Trial Court Services, Administrative Office of the Courts, Trenton, NJ. (2004). Guidelines for proceedings that involve deaf persons who do not communicate competently in American Sign Language.

The New Jersey Judiciary developed guidelines to assist judges, lawyers, and others involved in the legal system to (1) understand the unique communication needs of Deaf people who use a sign language other than ASL, and (2) provide guidance for improving successful accommodations for such persons.

LaVigne, M. & Vernon, M. (2003). An interpreter isn’t enough: Deafness, language and due process. Wisconsin Law Review, 5, 844-936. 

This report presents an overview of the challenges of providing due process in legal proceedings to deaf individuals who have language limitations. Using case examples of deaf people with varying levels of language deprivation, the report describes the challenges of interpreting highly abstract legal concepts like pleading “no contest,” clarifying how to optimize the interpreter’s ability to work, as well as explaining the limitations of even the most skilled interpreting. Differences between English and ASL, especially when ASL lacks technical vocabulary for abstract legal concepts, are discussed. The relationship between language deprivation, cognitive impairments, fund-of-knowledge gaps, and being incompetent to stand trial are explored. Incompetency is normally understood in relation to either neurological impairment or mental illness, but here the idea of legal incompetence due to language impairment is discussed. Recommendations are offered for compliance with federal laws to the extent possible.

Miller, K. R. (2004). Linguistic diversity in a Deaf prison population: Implications for due process. Journal of Deaf Studies and Deaf Education, 9(1).

The entire deaf prison population in the state of Texas formed the basis for this research. The linguistic skills of prison inmates were assessed using the following measures: (1) Kannapell’s categories of bilingualism, (2) adaptation of the diagnostic criteria for Primitive Personality Disorder, (3) reading scores on the Test of Adult Basic Education, and (4) an evaluation of sign language use and skills by a certified sign language interpreter who had worked with deaf inmates for the past 17 years. Deaf inmates with reading scores below the federal standard for literacy (grade level 2.9) were the group most likely to demonstrate linguistic incompetence to stand trial, meaning that they probably lacked the ability to understand the charges against them and/or were unable to participate in their own defenses. Based on the language abilities and reading scores of this population, up to 50% of deaf state prison inmates may not have received due process throughout their arrest and adjudication. Despite their adjudicative and/or linguistic incompetence, these individuals were convicted in many cases, possibly violating their constitutional rights and their rights under the Americans with Disabilities Act.

Miller, K. R. & Vernon, M. (2002). Assessing linguistic diversity in deaf criminal suspects. Sign Language Studies, 2(4), 380-390.

This is a study of how interpreters in forensic settings identify and respond to indicators that a person they are working with has minimal language skills and doesn’t understand the questions being asked of him. Interpreters look for inappropriate responses. Interpreting difficulties from poorly developed language skills are compounded by social and legal knowledge. Communication difficulties may reflect non-comprehension of syntax, impoverished socialization, emotional reactivity, inadequate vocabulary, and attempts to respond to the apparent situation or those portions of the communication that they understand. Attention is also devoted to the frequently encountered difficulty with understanding time, especially with sentences where time is imbedded within time, as in, “how many days out of the past month have you used alcohol?” Strategies for interpreters within criminal justice settings to field test language comprehension, legal knowledge, and literacy are offered.

Tuck, B. M. (2010). Preserving facts, form, and function when a deaf witness with minimal language skills testifies in court. University of Pennsylvania Law Review, 158(3), 905-956.

Many courts lack the ability to fully accommodate deaf witnesses who are semi-lingual, non-lingual, or otherwise possess minimal language skills. Courtroom participants use language in precise ways to exert control and power. The use of language monitor interpreters, deaf interpreters, and other best practice approaches do not always protect against inadvertent adjustments in facts, form, or function. The contemporaneous objection requirement bars parties from fully analyzing complex linguistic interactions before they enter the court’s official record. As an alternative, parties can borrow procedural tools from the document translation evidentiary model. Parties can apply additional resources to certain contested portions of the interpretation, and the court and jury can have additional information to help them settle the dispute.

Vernon, M., & Miller, K. (2001). Linguistic incompetence to stand trial: A unique condition in some deaf defendants. Journal of Interpretation, Millennial Edition, 99-120.

Deaf individuals in the United States who have a severely constricted understanding of English, little knowledge of the court system, a basic lack of information, and limited ASL skills are often unable to understand the charges they face in court, nor can they participate in their own defense. Consequently, they are legally incompetent on linguistic grounds. Thus, as in the case of a person who is legally insane or severely developmentally delayed, they cannot stand trial unless and until the condition can be successfully treated. This concept of linguistic incompetence is relatively new to the courts and poses a major problem. In this paper, this concept is explained and documented, and its prevalence in the deaf population is discussed. The paper discusses common difficulties with written English that deaf people have. It discusses reasons why the vocabularies of sign languages are severely constricted. It discusses pressures on interpreters and how they often respond in ways that do not provide linguistic equivalence for deaf defendants. Solutions for the dilemma it creates for the courts and interpreters are discussed.