Is an Unbiased Jury Ever Truly Possible?

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Jurors watching a trial

In Australia, jury trials are one of the mainstays of the criminal justice system.

In a jury trial, a defendant’s guilt or innocence is decided by a panel of 12 members of the public who are expected to be impartial, and to make their decision solely on the evidence that is presented to them by the defence and prosecution.

Jury trials are sometimes considered a fairer way of deciding whether a person is guilty of a crime than a magistrate or judge-only trial, as there is believed to be less chance of a single person’s individual bias and prejudices affecting the decision.

This is not necessarily always the case, however.

Individual jurors may have had less training in the legal process, and may not even be aware of their own prejudices and how these could be clouding their overall decision.

As jury trials are seen as an inherent part of justice in this country, it’s essential that the public’s confidence in the impartiality and fairness of the process be maintained.

Individual or collective bias against a defendant by members of the jury could interfere with the presumption of a defendant being innocent until proven guilty, and affect the course of justice.

Unfortunately, when it comes to jury trials, there’s no way to tell what individual bias members of a jury might have, which could ultimately influence their decision.

A number of recent studies have revealed collective bias in juries towards a number of different factors, including gender, societal expectations, weight, race, and even where the defendant is positioned during the trial.

These could all have potentially serious implications for the impartiality and fairness of jury trials, and have the potential to make a major difference to the outcome – even where the evidence provided is the same.

Here are some of the prejudices that studies have shown to be present in juries in a number of different types of cases.

Defendant positioning

A study from the University of Western Sydney recently revealed bias in juries based on how the defendant was positioned during a trial.

The study used a series of mock trials for an alleged terrorist, played by an actor, and the same evidence was presented at each trial.

In one trial, the defendant was positioned in a glass dock.

In another trial, the defendant was seated in an open dock, and in a third he was positioned at the bar table.

The outcome was significantly different each time.

When the defendant was in a glass dock, 60% of the jury delivered a guilty verdict.

When he was in an open dock, this decreased to 47%.

When the defendant was seated at the bar table, only 36% of the jurors delivered a guilty verdict.

When surveyed, the general impression given by the jurors was that the defendant appeared more threatening and dangerous when he was seated in the glass dock than when he was in the other locations.

This evidence suggests that glass docks should only be used in extreme cases, due to the risk of jury bias.


In another study published last year in the International Journal of Obesity, it was revealed that perceptions of guilt in a fictional fraud case were affected by the gender and weight of the defendant.

In this study, participants were shown mug shots of male and female defendants, some of which had been manipulated digitally to make them appear obese.

They then read a vignette about an instance of fraud, and were asked to assess the likelihood that the defendant was guilty.

The results showed that among the male respondents to the study, there was a marked prejudice against the obese female defendant.

The lean female defendant was considered much less likely to be criminally culpable.

Among the male defendants, there was no obvious bias against weight.

The female respondents also didn’t draw any distinctions between the criminal culpability of the obese and the lean female defendants.

This study indicated the possibility that male jurors may be prejudiced against overweight female defendants, and that this could potentially impact the outcome in a jury trial.

Societal expectations

Societal beliefs and misconceptions can play a strong part in jury decisions in any case, but they have been shown to be particularly prevalent in cases dealing with sexual offences.

Studies into juror perceptions in sex abuse cases have shown that even when the defendant is found guilty, negative stereotypes against victims still exist among jurors.

Some of the out-dated ideas around how a rapist should behave and what situations constitute sexual assault appear to still be prevalent among modern jurors.

A 2001 study which interviewed jurors in sex offence cases to find out their deliberations showed that some jurors believed that having a domestic relationship with the offender meant that the offence didn’t class as abuse, while others judged victims on their sexual past and whether or not they were ‘sluts’.

Since the date of that study, however, there have been significant changes in sexual assault laws to prohibit the admission of evidence relating to the past sexual conduct of complainants, to prevent adverse inferences being drawn from delays in complaint, and many other changes which have made it harder to defend sexual assault cases in court.

Racial discrimination

Racial discrimination can still unfortunately play a significant part in the outcome of jury trials.

A study in the US, where unlike Australia juries also have a say in the sentencing of those found guilty, revealed that white jurors were more likely to request the death penalty for black defendants than for other white defendants.

Jury bias is a concern for anyone who is facing the criminal justice system in Australia.

Unfortunately it is very difficult to completely remove the inherent bias in jury members, which can put innocent people at risk of being wrongly convicted due to bias against their weight, race, gender or how they are presented in court.

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Ugur Nedim

Ugur Nedim

Ugur Nedim is an Accredited Criminal Law Specialist with 25 years of experience as a Criminal Defence Lawyer. He is the Principal of Sydney Criminal Lawyers®.

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