Saturday, December 06, 2003

Lee Malvo and Mens Rea

CNN is carrying this report on expert testimony from a defense psychologist in the trial of accused DC sniper Lee Malvo, who has raised an insanity defense. Malvo's lawyers are pushing the theory that Malvo's mentor, John Allen Muhammad, indoctrinated or brainwashed the teenage Malvo into serving as a child soldier in a war for racial justice. The prosecution has objected to expert testimony on this subject, but with little success.

Virginia law evidently permits expert testimony on a criminal defendant's mental capacity, but only in the context of an insanity defense. See, e.g., Peeples v. Commonwealth, 30 Va. App. 626, 519 S.E.2d 382 (Va. Ct. App. 1999) (en banc). Whatever one may think of expert testimony on mens rea, has Virginia drawn the line in a coherent way? In the Peeples case, the court of appeals relied on reasoning previously tendered by the Virginia Supreme Court in Stamper v. Commonwealth, 228 Va. 707, 324 S.E.2d 682 (1985): "The state of knowledge in the fields of medicine and psychiatry is subject to constant advance and change. The classifications and gradations applied to mental illnesses, disorders, and defects are frequently revised. The courts cannot, and should not, become dependent upon these subtle and shifting gradations for the resolution of each specific case."

It is not immediately obvious why that rationale, if legitimate, should be subject to exception in cases involving an insanity plea. Your humble reporter can claim no expertise in any aspect of criminal law, but if psychiatry lacks the requisite doctrinal fixity to supply helpful and reliable guidance on defendants' mental states in general, then surely that circumstance is unaltered by any particular criminal defendant's choice of plea. Conversely, if psychiatric evidence is sufficiently reliable to be potentially helpful to the trier of fact in insanity cases, why should it not be considered equally reliable and helpful, e.g., on general issues of mens rea?

Perhaps the question is naive. Perhaps the intent is simply to set a high price (invocation of a defense that jurors may find unsympathetic, and/or probable indefinite post-trial incarceration in a psychiatric facility) for a criminal defendant's use of expert psychiatric testimony to excuse his wrongful acts. Such a justification would not seem completely indefensible. There could be a legitimate feeling that persons who commit felonies should either accept the penal consequences, if they possess the capacity to conform their conduct to law, or accept incapacitation during the pendency of treatment, if they do not.

But if that is the policy justification for the rule, then it might be better to say so forthrightly, rather than blaming the alleged inability of psychiatry to reach stable consensus. The justificatory foundations for evidentiary rules should be explicit and transparent. It is misleading, and fosters confusion, to cloak the justifications for evidentiary rules in epistemic terms, when their real animus is different.
Fed. R. Evid. 702: If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.