Forensic Psychology: Article Review - Competency Evaluations for Individuals with Mental Retardation
Posted Oct 03 2008 12:51pm
I just finished reading a 2007 article authored by Mark Siegert and Kenneth Weiss. The article addresses the issue of conducting an evaluation of competency to stand trial (CST) with defendants who are either mentally retarded or are of borderline intellectual functioning. This article is both interesting and relevant, in that it not only identifies specific issues related to assessment with these particular types of clients, it also discusses a court case in which a finding of competency was overturned due to the expert’s lack of expertise with this population, as well as the expert’s inappropriate use of assessment measures. One specific aspect of this article that caught my attention was its reference and to the Competence Assessment to Stand Trial for Defendants with Mental Retardation (CAST-MR). Not only do I use this test regularly with individuals demonstrating low intellectual functioning, I have previously written about it here. Given that, I decided I would write a post on this article.
The court case the authors refer to his entitled State v. M.J.K. In this case, the judge relied on the testimony of the state’s expert, who found the defendant competent, as opposed to three other experts who found the defendant incompetent. One of the three experts who found that the defendant incompetent is actually an author of the CAST-MR. The judge’s decision was overturned on appeal. Without rehashing the entire article, here were a couple of the reasons cited by the appellate court:
1) The state’s expert apparently conducted the evaluation in 90 minutes.
2) The evaluator based their determination of competency on the results from the CAST-MR. This, after diagnosing the defendant with borderline intellectual functioning. The CAST-MR is to be used only with individuals who have been diagnosed as mentally retarded, per the test manual.
3) In addition, the test, manual of the CAST-MR also requires anyone who administers it to have one year of specialized experience in working with the mentally retarded. The state evaluator had no such experience.
This article prompted me to consider several different aspects of conducting this type of competency evaluation. First, I completely agree that a 90 minute evaluation is much too short to possibly be considered thorough. It is possible to be limited to 90 minutes or less due to a lack of cooperation on the part of the defendant, but in that case one’s confidence in their findings should be an inverse proportion to the amount of time actually spent with the defendant. The limited confidence in the opinion ought to be expressed in the evaluation report as well. The article does not state if the 90 minute evaluation was due to a lack of cooperation, oral lack of thoroughness on the part of the evaluator. I simply don’t see how one can examine all the relevant issues with respect to competency without spending significantly more time with the defendant than 90 minutes.
With respect to the use of the CAST-MR, I can certainly understand the authors of the test suggesting that it not be used with individuals who have a relatively higher I. Q., such as in the borderline range. However, as I noted in my previous post on this subject, I think this suggestion is appropriate only if the evaluator is planning to use the CAST-MR as the sole instrument for competency assessment. The authors suggest individuals with borderline intellectual functioning, or even minimal mental retardation, will to be a victim of the test in that it has a bias towards competency as one’s IQ approaches 75. What the authors are suggesting is that IQ is only one relevant measure of an individual’s full cognitive functioning, and that an IQ at the upper range will mask the other deficits, allowing the defendant to score adequately on the CAST-MR despite the presence of other impairments and cognitive functioning. While this may be true, this is only a problem if the evaluator only uses the CAST-MR in their assessment of the defendant’s functional abilities.
If we remember that a finding of competency requires both a factual and rational understanding of court room procedure, in addition to an ability to work with one’s attorney on their defense, then we can consider the use of the CAST-MR as an initial assessment of the defendant. That is, the CAST-MR can be used to assess a defendant’s factual understanding of the necessary information. If the defendant is able to display such a factual understanding, the evaluator can then assess the defendant in terms of their rational understanding with an instrument designed to assess this higher level, such as the R-CAI. If the defendant is unable to demonstrate such an understanding, then we know they are incompetent at this time without using a higher-level test. So, even if the defendant’s relatively high IQ is masking certain deficits that allow for satisfactory score on the CAST-MR, those deficits will become apparent on the R-CAI, or whatever secondary assessment measure the evaluator utilizes. In fact, the test manual of the CAST-MR clearly states that it is to be used as only one part of a thorough evaluation.
The authors of the article also make clear they believe that an evaluation of competency to stand trial with the defendant who is mentally retarded requires even further specialization than simply being a forensic psychologist or psychiatrist. Very often one will read articles discussing concerns related to all sorts of clinicians engaging in forensic evaluations without the relevant experience. This article suggests not only should an evaluator be specialized as a forensic psychologist or psychiatrist, but that even if one demonstrates such as specialization, they are not necessarily qualified to conduct this type a forensic evaluation. The authors of the article discuss the unique issues associated with the developmentally disabled population, and indicate there believe that only an individual with specialized experience working with this population is qualified to conduct such an evaluation. They also cite the manual for the CAST-MR, which requires any administrator of the CAST-MR to have one year of specialized experience in working with this population prior to using the instrument.
At best, I can only partially agree with the sentiment. Obviously, some experience and training in the use of these measures, in addition to the other relevant aspects of conducting these sorts of evaluations, is essential in a clinician doing satisfactory work. However, it seems as if everyone who works with a particular subgroup believes their niche is so important that only a select few are capable of working in that area. To me, if the evaluator addresses all the relevant issues, and bases their conclusion on an appropriate understanding of both the psychological and legal standards, that evaluator has done their job. And this is from an individual who has the specialized experience these authors suggest.
I do think, though, the article does should some light on an important aspect of conducting forensic evaluations. It is extremely important to evaluate the individual as an individual, and in sure that your finding (either way) is based on accurate and thorough information. The evaluation should also be tailored to the specific issues the defendant is presenting. There is no such thing as they rote evaluation, at least not adequate one. The interview, tests, collateral contacts, and all other aspects of the forensic evaluation should be tailored to the specific needs of the defendant. This article does a good job of highlighting those needs with respect to the developmentally disabled.