Mental deficits may lead to false confessions or reduce culpability
In 2002 the US Supreme Court, in Atkins v. Virginia, outlawed the imposition of the death penalty for people who are mentally retarded. Justice John Paul Stevens, who wrote the decision, stated that people who have mental retardation have less moral culpability than those of “normal” intelligence who commit similar acts. More specifically, Justice Stevens opined that people who are mentally retarded frequently know the difference between right and wrong, but because of their impairments, “have diminished capacities to understand and process information, to communicate, to abstract from mistakes, and learn from experience… there is abundant evidence that they often act on impulse rather than pursuant to a premeditated plan, and that in group settings they are followers rather than leaders.” He went on to cite that although these “deficiencies do not warrant exemption from criminal sanctions, they do diminish their personal culpability.”
By definition, people who have mild mental retardation must have (a) significant intellectual deficits (i.e., an IQ of 70-75 or less), (b) related impairments in “adaptive functioning,” and (c) the onset of the disorder within the “developmental period,” which is typically defined as prior to age 18 in most states. “Intellectual deficits” are determined by scoring at least two standard deviations below the mean on standardized intelligence tests, such as the Wechsler Adult Intelligence Scale – Fourth Edition (WAIS-IV) or the Stanford Binet (SB).
Surprisingly, mental retardation, also called Intellectual Disability (ID), can be a largely hidden disorder. Approximately 85% of people who have ID are in the mild range, and often they “blend in” with the rest of society relatively unnoticed. Many people, including judges and juries, may relay on their stereotypic beliefs about ID, that people with ID are readily identifiable by a behavioral and physical phenotype. However, these characteristics are more indicative of moderate to severe ID, and comprise only 15% of people who have an intellectual disability.
Most people who have mild ID do not have any of the obvious characteristics of mental retardation that most people associate with the disorder. People with intellectual disabilities may even have some areas of adequate functioning, as well as some areas of significant limitation. For example, some people with mild ID may be able to hold employment or drive a car.
However, a mildly intellectually disabled person’s assessment of his or her own functioning is usually not a valid source of information. Oftentimes a person with mild ID might exaggerate their competence in order to mask their disability and avoid embarrassment. They can frequently do this successfully because of their decent ability to engage in casual conversation and discuss concrete topics. But when asked to explain their statements or discuss topics that require more abstract reasoning, their limitations become more evident.
Therefore, an intellectually disabled suspect who looks and sounds normal to police may be unable to comprehend their Miranda rights, rendering them incapable of making a knowing, voluntary, and intelligent waiver of their rights. Suspects with limited intelligence may also be more susceptible to the police interrogation tactic of lying about evidence. Although this is a standard method of interrogation, it can overwhelm an intellectually disabled person’s capacity to navigate the complexity of being questioned by police. Additionally, there is a higher likelihood that the mentally retarded person assumes the police officer, who is a trusted authority figure, is being honest. The suspect with mild ID may therefore conform their statement to fit the “truth” told by the officer. In some instances the suspect may progressively change their statement to account for falsehoods told to them by police. I once evaluated a defendant who was told that he could go home if he confessed, and although he was allowed to leave the police station, he was arrested shortly thereafter anyway. This confused the defendant, given that he did what he was instructed to do to be set free.
A famous example of an intellectually disabled suspect who may have been unduly influenced by police was Jessie Misskelley, Jr. Due to his cognitive deficits, he provided a false statement to police implicating himself, Damian Echols, and Jason Baldwin in the murder of three young boys in 1993. In 1994 Misskelley and Baldwin each received life sentences, while Echols was sentenced to death. The three were later released in 2011 on an Alford plea when new genetic evidence could not link any of the three to the crime.
Although it is certainly not true in every case, Intellectual Disabilities may compromise a defendant’s capacity to fully appreciate their role in a crime, or it may limit their ability to meaningfully participate in their defense. Sometimes acts of apparent competence committed by a person with ID, such as committing a robbery, might actually be a sign of incompetence, like panicking and firing the gun when something goes awry. Moreover, these acts of apparent competence often result from being orchestrated or manipulated by a more competent peer. Even when ID does not compromise a defendant’s fitness for trial or their capacity to waive their rights, ID can be an important mitigating factor at the time of sentencing.
