International Judicial Monitor
Published by the International Judicial Academy, Washington, D.C., with assistance from the
American Society of International Law

Spring 2013 Issue

Global Judicial Dialogue


Issues of Culpability in the Context of Criminal Justice and Neuroscientific Evidence

Judge Susan A. EhrlichBy Susan A. Ehrlich, J.D., LL.M. (biotechnology & genomics), Judge, Arizona Court of Appeals (ret.)

Lex talionis is the law of retribution. The Code of Hammurabi, the Law of Moses and the Qur’an similarly press retributive justice.  As expressed in the Bible in the Book of Exodus:  “[I]f any mischief follow, thou shalt give life for life, eye for eye, tooth for tooth, burning for burning, wound for wound, stripe for stripe.”  The decree was absolute; there were no exceptions for youth, for the mentally disabled, or for anyone unable to govern his or her acts. 

To obtain retribution no longer is the sole or even the primary reason for which the law exists, however.  The overarching purpose of the law is to guide individual conduct in the framework of the greater social good and to hold an individual responsible for his or her conduct by means of a just process.  The overarching purpose of the criminal law is to protect the common good through the enforcement of violations of that social code through measures that include education regarding the shared norms and values, the maintenance of peace by publicly licensed law-enforcement officers, the punishment of a transgressor upon due process, deterrence through the punishment of an offender and the education of all, and the rehabilitation of the wrongdoer.  Retribution is not for the criminal but for his or her victim(s), as a mechanism of deterrence and for the satisfaction of society because justice has been achieved. 

If it is undisputed that a wrong has been done, is it, however, appropriate to punish an individual if his or her act was neither intentional nor attributable to a lack of judgment because the offender was or is not capable of forming the requisite intent, of understanding the consequences of his or her act, of understanding that the act was wrong, or of conforming his or her behavior to the law?  Does the offender’s ability to understand and accept responsibility for a criminal act have to be an indispensable condition of a just punishment?  David Hume wrote in An Enquiry Concerning Human Understanding that “[t]he only proper object of hatred or vengeance is a person … endowed with thought and consciousness,” and that is the perspective for which neuroscience is pertinent. 

Three examples of individuals whose behavior likely was marked by irregularities of the brain are the following: 

(1) Phineas Gage in 1848 survived an explosion that drove an iron bar through the front portion of his head.  Immediately, Gage’s personality changed markedly; he became impulsive, showed inappropriate social behavior and otherwise lost a noticeable number of his normal, conventional inhibitions.  No autopsy was done, but the destruction to his skull shows that the area of his pre-frontal cortex was damaged.

(2) Charles Edmund Cullen is suspected of being the most prolific serial killer in United States history.  A nurse, he has admitted killing as many as forty of his patients beginning in 1988, but it is likely that he has killed many more people, possibly hundreds of patients whose identities he cannot remember.  Moreover, while in his interviews he speaks of right versus wrong, he seems to lack an obvious or real cognition that the deaths he caused indeed were wrong.  A scan of his brain might show that his amygdala is smaller than that of a normal man.

(3) A Virginia teacher in 2000 began surreptitiously visiting web sites featuring pornography and collecting pornography, most of which highlighted images of children and adolescents.  After he approached his young stepdaughter, he was arrested and convicted for child molestation.  The man was given the choice of participating in a rehabilitation program for sexual addiction or prison.  Despite his strong desire to avoid prison, he failed in the program because he continued to solicit sexual favors from members of the staff and fellow patients.  He was awaiting the sentence to prison when, suffering from a headache and problems of balance, fearing that he might rape his landlady and contemplating suicide, he went to an emergency room, still unable to control his impulses as indicated by his approaches to the female staff.  An MRI showed the presence of a right orbitofrontal tumor.  When it was removed, his inappropriate sexual urges disappeared, and his behavior returned to normal.  The man again was permitted to enter a rehabilitation program, which he successfully completed and thereafter returned to live with his wife and stepdaughter.  When he began to display his former interest in pornography, though, he self-reported, and an MRI showed that the tumor had reappeared.  It was removed, and his urges again subsided. 

Irregularities in the brain need not be physiological at birth. There may be injury due to physical trauma such as exposure to lead, abuse or an explosive device, or emotional disturbance such as abuse or post-traumatic stress disorder.  But when does a structural difference, whatever the source, become a functional difference, and what is a tolerable range of behavior? “Abnormal” with reference to brain function or behavior is not self-defining except at the extremes, but a presumption of what is “normal” is a conceit necessary for the regulation of individual behavior within society, the notion of responsibility itself being a social construct.  The law therefore treats individuals as intentional persons, and legal responsibility depends on a person’s capacity to be rational.  Indeed, the definition of “insanity” in the American Law Institute’s Model Penal Code, which has been widely adopted, is that a person is not liable for a criminal offense if, when the offense was committed, he or she “suffered from a mental disease or defect that resulted in the individual lacking the substantial capacity to appreciate the wrongfulness or his or her actions or to conform” those actions to the law.   In this, a mental disorder may play a causal role. 

This presents the question of the degree to which a person should or will be held responsible if his or her capacity to be rational is not completely developed.   In addressing not responsibility for committing a crime but culpability in the context of punishment, the United States Supreme Court held in Atkins v. Virginia (2000) that a mentally disabled person, because of his or her disabilities in reasoning, judgment and impulse-control, does not act with the level of culpability that supports the imposition of the death penalty.  Instead, it wrote, punishment must be tailored to the individual’s “personal responsibility and moral guilt.”  Subsequently, the Court held in Roper v. Simmons (2005) that the “diminished culpability” of offenders younger than age 16 due to their “lack of maturity and an underdeveloped sense of responsibility” also bars the imposition of the death penalty.  

Neuroscience can provide significant insight and an improved understanding of the human condition.  Neuroimaging may display a condition that can compromise or negate rational behavior.  Accepting the reliability of the proof, the introduction of neuroscientific evidence implicates varied and numerous legal issues for a just determination of guilt and punishment.  While not exclusive to the justice system of the United States, its system provides a useful scaffold to present for consideration if not resolution of many of these issues. 


Competence to stand trial.  Under certain conditions, a defendant may be medicated with psychotropic drugs in order to restore his or her competence to stand trial, the societal interest in adjudicating the defendant being sufficient to infringe upon the accused’s liberty interest in deciding whether to take such drugs.  Sell v. United States (2003).  Given that degree of permissible intrusion, would or should it be acceptable for a defendant who is determined to be incapable of understanding the proceedings against him or her to undergo neuroimaging for the possibility of ascertaining whether the administration of medication would restore competency and insisting on that treatment?

Self-incrimination, unreasonable searches and due process.  The privilege against self-incrimination is limited to testimonial or communicative evidence; it does not apply to physical evidence such as samples of hair, blood and other bodily fluids or handwriting.  Separate but not infrequently related are tenets against searches that pertain to body-cavity and x-ray searches that, as a general rule, require a particularized and objective “reasonable suspicion” of wrongdoing by an individual.  Additionally, there are certain procedures such as pumping a stomach that pose such a great intrusion into a person’s integrity as to “shock the conscience” and be unlawful as a violation of due process.  In what category is a neuroimage?  Is this type of  penetration of the body too great an intrusion?

Right to present evidence.  The accused has the right to present evidence in his or her defense, but he or she need not testify.  If, however, a defendant chooses to testify and thus subject himself or herself to cross-examination, can he or she be forced to undergo neuroimaging as a means of detecting whether the defendant is telling the truth?  Can he or she be impeached with a refusal to undergo neuroimaging? 

Witnesses.  A witness may lie.  A witness also may suffer from bias, a bias that may not appear in the course of cross-examination, particularly if the bias is not a conscious one.  Also, an individual’s memory may be suspect.  Depending on the nature of the testimony, a witness’ credibility may be not only important but decisive, but is that consequence for the defendant’s fair trial and liberty interest – indeed, the possible conviction of an innocent person – sufficient to require that a witness submit to neuroimaging or is that too great a violation of the witness’ civil liberties?   

Jurors.  A prospective juror may lie in reference to his or her ability to serve, perhaps wanting to participate in a trial that could be sensational.  A potential juror may suffer from bias such that he or she should not be sitting in judgment of a witness’ credibility and/or of the defendant.  Again, are the accused’s interests sufficiently greater than are a juror’s interests?   

Additionally, scientific evidence – that science that has been deemed by a court to have sufficient reliability to be admitted – carries an aura of objectivity.  This may correlate with infallibility and disproportionately sway jurors. 

Sentence.  There are three forms of verdict:  not guilty, guilty or not guilty by reason of insanity.  By this process, a person’s responsibility for the charged offenses is declared by the trier-of-fact.  If the verdict is that the accused is not guilty, the person is free.  If the verdict is that the accused is not guilty by reason of insanity, a verdict that could be reached due to neuroscientific evidence, as a general proposition, the individual may be committed to an institution but not imprisoned.  If the verdict is that the accused is guilty, but the evidence, including the neuroscientific evidence, shows that the defendant was not rational or has a reduced sense of responsibility, should this determination mitigate the punishment as the United States Supreme Court has declared in the setting of the imposition of the death penalty?              

Punishment serves several purposes: penalizing the criminal, delivering justice for society and, specifically, justice for the victim(s) of the offense, rehabilitating the wrongdoer, deterring the offender and others from unlawful conduct, and providing retribution.  Is it appropriate to distinguish among individuals committing the same crimes depending upon whether they are rational and able to conduct themselves in a responsible manner?  If so, what are the factors that should be utilized in making those distinctions?  Should there be different forms of punishment such that offenders who committed the same type of crimes are treated differently based upon the root causes of their behavior?  The United States Supreme Court held in Washington v. Harper (1990) that a prisoner may be forced to take psychotropic drugs only as is necessary and effective for the safety of the inmate and/or others in the prison. But should medical or behavioral treatment be forced upon inmates if such treatment is not otherwise necessary for the protection of the institution’s staff and inmates in order to “restore” those individuals?  If the offered therapy is not forced, is there duress nonetheless inherent in the offer of pharmacological treatment or, as in the case of the Virginia schoolteacher, surgical intervention – especially if acceptance of the proposition is a condition of changed prison circumstances?  What is the nature of the monitoring process? 

Parole.  Risk-assessment is the key factor in the decision whether to release an offender before his or her term of imprisonment is completed.  Historically, this has depended on the nature of the crime(s) and the individual’s age, history (including criminal history, compliance with rules while incarcerated, education and employment history), perceived social skills and support system upon release.  Two recent studies suggest physical factors that can be deduced from neuroscientific studies:  Kent Kiehl and colleagues have concluded that male offenders with low activity in the anterior cingulate cortex are twice as likely to commit another crime as those with high activity. Dustin Pardini and colleagues submit that men with smaller amygdala exhibit higher levels of aggression and psychopathic features and thus pose an increased risk for violence. These necessarily are small studies that for ethical reasons are neither randomized nor double-blind, however, and the calculations of what constitutes variances from “normal” in “low activity,” “smaller amygdala” and “increased risk” necessarily are arbitrarily fixed definitions.  It also must be remembered that in the late 1960s and early 1970s, it was thought that men who had a second Y chromosome were more likely to be violent, but subsequent research showed this not to be accurate. 

Parole is a conditional release.  As asked about prison inmates, should there be a variance in treatment depending on the nature of the criminal behavior?  Would consent to prescribed treatment not be real agreement but the result of pressure if made a condition of parole?  Given the restrictions of a parolee’s liberties upon release, is treatment as a condition of discharge acceptable nonetheless?  What would be the enforcement mechanism? 

Aristotle viewed human nature as the intersection of biology and politics as each regulates behavior.  Putting neuroscience in its fitting legal context requires that neuroscientists, lawyers and judges engage in cross-disciplinary study and work to formulate an analytical framework with which to address cases in a more judicious way as neuroscience furthers our understanding of the founts of human behavior.  

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