The Illinois Supreme Court reversed the conviction of a criminal defendant who was mentally retarded after it found that she was incompetent to waive her Miranda rights. As a result, the confessions she had given the police were suppressed and a new trial was required if the state wished to continue to prosecute her for a pair of murders that occurred in a Chicago apartment where she was present.
The court determined that there were two primary issues that must be resolved. First, was this a "custodial interrogation"? The court noted that only if the defendant was in the custody of the police at the time of the confession was the 5th Amendment's privilege against self-incrimination applicable. Second, was the defendant's waiver of her Miranda rights made voluntarily, knowingly, and intelligently?
The focus of the first question, the court decided, is whether a reasonable person would have felt he or she was not at liberty to terminate the interrogation and leave. Factors the court found applicable to this question were the "age, intelligence, and mental makeup of the accused--and an investigating officer's awareness and exploitation of those characteristics."
The court reasoned that because it is "now firmly established legal principle that 'juvenile defendants are, in general, more susceptible to police coercion than adults'" and thus a "reasonable-juvenile standard" is now applied to a determination of whether an interrogation of a juvenile is custodial, a similar modification of the reasonable person standard should apply when mentally retarded defendants are involved. The court cited "their limited communication skills, their predisposition to answer questions so as to please the questioner rather than to answer the question accurately, and their tendency to be submissive" as the bases for finding that mentally retarded defendants are more susceptible to police coercion during a custodial interrogation.
The court added that mentally retarded defendants are also more susceptible to the impression that they are in custody in the first place. In this case, the court emphasized that the defendant had been questioned by the police six times before she was formally arrested. Also noted was that for the questioning the police enlisted the help of a woman who said she was the defendant's sister and legal guardian, that this woman facilitated the interrogation by conveying the questions of the police after it became apparent that the defendant would not respond to the police, and that this woman did not fill the role of a family member concerned with the defendant's welfare. …