What Were You Thinking? How Jurors Read Your Guilty Mind

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Illustration by A Health Blog via Flickr

Imagine you’re a member of a jury asked to assess the following case:

U.S. border guards detain an individual whose duffel bag contains a large container of cocaine, but when the case comes to trial, the defendant argues that he had no idea drugs were in the bag.

Under federal law, it’s a crime to “knowingly or intentionally . . . possess a controlled substance,” but if an individual says he is not guilty and there are no witnesses to prove otherwise, how will you determine what he knew or believed?

That thought experiment was one of six designed by a team of law and neuroscience experts to study how jurors assign a mental state without a “transparent window” into the accused’s mind, as well as examine how these decisions are influenced by feelings about criminal culpability.

Some 628 individuals participated in the experiments, conducted online, between November, 2015 and October, 2016. Over half (53 percent) were male, and 77 percent were white. They represented a broad variety of income groups and educational background. All were U.S. citizens or U.S. residents over the age of 18.

The authors’ conclusions, presented in a forthcoming paper for the Vanderbilt Law Review, could be grim news for most criminal defendants in similar circumstances.

Even though nearly all U.S. drug statutes require “knowledge” in order to convict, “for the average jury-eligible American, mere recklessness as to the presence of drugs in the bag is sufficient for conviction,” the paper says.

“In fact,” write the authors, “there is no material difference in the proportion of subjects holding a defendant guilty when the evidence strongly suggests that he ‘knows’ that the circumstance exists, as compared to suspecting that it does.”

What’s more, the percentage of would-be jurors who assigned a mental state of “knowledge” jumped from 18 percent to 33 percent when they were told that knowledge was required to convict—even though evidence only indicated an “awareness of risk.”

Many of those who decided the behavior was reckless also chose to convict, despite instructions to take into account the defendant’s declared non-awareness of criminal behavior.

The authors of the study, entitled “Decoding Guilty Minds,” were Matthew R. Ginther of the Court of Federal Claims, Office of Special Masters; Francis X. Shen of the University of Minnesota Law School; Richard J. Bonnie of the University of Virginia School of Law; Morris B. Hoffman, Second Judicial District Court Judge, Colorado; Owen D. Jones of the Vanderbilt University Law School and Department of Biological Sciences; and Kenneth W. Simons of the University of California, Irvine School of Law. The experiments were funded by the MacArthur Foundation Research Network on Law and Neuroscience.

For the purposes of the study, they focused on mental states as they pertain to material circumstances.

Using four mental states (or mens rea) as defined by the Model Penal Code (MPC) and nine different criminal charges, researchers presented subjects with a series of one-paragraph scenarios about a fictional defendant named “John.”

Each experiment was altered to variously tease out “unguided moral intuitions,” feelings about culpability, and the effect of mens rea instructions to potential jurors.

Previous studies by the research group already showed that subjects of the experiment tended to disagree most, or show the least confidence, when it came to distinguishing between “recklessness” and “negligence.”

Significantly, the authors said, the threshold for conviction by these same jurors consistently fell between negligence and recklessness, rather than the threshold according to our legal framework (between recklessness and knowledge).

Why did subjects assign knowledge when evidence was weak?

One possible explanation, according to the study, is that people have a hard time understanding the difference between knowing and recklessness conduct, “and, because they cannot detect a difference between them, they are treated as morally equivalent.”

But two of the experiments showed that subjects did understand and correctly differentiate between these mental states as defined in the MPC.

A more likely explanation is that people do not find a moral distinction between knowing and reckless behavior, and ignore mens rea requirements in favor of their “bare intuition.”

Should our legal framework shift to recognize the shared moral instinct of jury-eligible adults? Do jurors need better instruction?

The paper notes that while law scholars have long debated mens rea criteria, they have ignored the people ultimately assigned to adjudicate these statutes.

The authors acknowledge the results of their experiments are “intriguing, yet preliminary,” and add that more research is required.

“In the meantime, however, our research could have important consequences for legislatures, appellate courts, and trial judges who are trying to decide whether a defendant needs to know a fact to be criminally responsible, or merely needs to be reckless or negligent.”

The full study can be downloaded here.

This summary was prepared by Victoria Mckenzie, Deputy Editor of The Crime Report. Readers’ comments are welcome.

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