Jill Meagher Murder – Should Juries Know About Prior Offences?

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Adrian Bayley: It’s a name that sends chills down the spines of women right around the country.

The 41-year-old man found himself in the media spotlight after he was convicted of murdering 29-year-old ABC employee Jill Meagher in Melbourne in 2012 as she walked home from a night out with friends.

At that time, Bayley already had a string of convictions for sexual offences against his name and had served time in prison.

Last week, Bayley was convicted of three further sexual assaults committed between 2000 and 2012. However, despite the cases bearing similarities, the trials were each heard separately, and jurors were not informed of the other ongoing matters.

The outcome of these cases, considered in light of Meagher’s highly publicised murder, have led many to question why the juries were not informed about Bayley’s previous convictions or the concurrent proceedings.

When Can a Court Hear Evidence About Prior Offending?

The court can only admit evidence of a person’s prior conduct if it passes the ’tendency’ or ‘coincidence’ tests contained in the Evidence Act 1995 (“the Act”).


Section 97 of the Act deals with tendency evidence, which is evidence about a person’s character, reputation or conduct, or a tendency of a person to act in a particular way or to have a particular state of mind.

For example, the prosecution in a sexual assault case may wish to adduce evidence that the defendant had sexually assaulted females using the same ‘modus operandi’ (ie method) in the past; for instance, engaging in a specific sequence of acts or leaving unique identifiers such as bite marks on a particular area.


In contrast, coincidence evidence refers to evidence about 2 or more similar offences – for example, if 3 robberies occurred on service stations in a particular suburb over a single weekend, the prosecution might seek to use evidence that the defendant had already been convicted of 2 of the robberies in proceedings for the 3rd offence.

The rules relating to coincidence evidence are contained in section 98 of the Evidence Act. Such evidence can only be admitted where, having regard to the similarities between the events, it is improbable that the events occurred coincidentally.


The law says that tendency and coincidence evidence can only be admitted where it is ‘capable of rationally affecting a fact in issue’; in other words, affecting a material fact whose determination could impact upon the ultimate verdict.

The prosecution must also prove that the evidence has ‘significant probative value which substantially outweighs any prejudicial effect it may have on the defendant’; which means that it must be important, and the importance must outweigh the prejudice that the defendant is likely to suffer through its admission into evidence.


The case of R v Lockyer (1996) found that for something to be ‘significant’ it must be more than ‘merely relevant’ to a fact in issue – it must be ‘important’ or ‘of consequence’ in proving a fact in the case.

In deciding whether to admit tendency or coincidence evidence, the judge will consider the nature of the similarities between the evidence in question and the circumstances of the cases.

If the prosecution wishes to rely on such evidence, it must give reasonable notice in writing to the defence.

Should We Relax Our Evidence Laws?

If someone has a history of similar criminal conduct, it might make sense to allow that evidence to be admitted into court.

However, there is danger in this approach. In a criminal trial, the question that the jury must answer is whether the defendant committed the offence before the court, not whether their past track record suggests that they may have.

One of the reasons behind evidence laws is to prevent the situation where a person is found guilty based upon suspicion or prejudice rather than evidence pertaining to the allegations against them.

Excluding evidence of prior conduct allows the court to focus on the evidence directly relevant to the case-at-hand, without being clouded by external considerations.

And importantly, the tendency and coincidence rules do not automatically exclude all evidence of a person acting in a particular way – they simply impose criteria which must be before that evidence is admitted.

These tests reduce the likelihood of a person being wrongly convicted on the basis of their previous actions.

The safeguards are particularly important for trials involving conduct that is considered to be especially abhorrent, such as child sexual assault. In such trials, members of the jury might be disgusted that the defendant had previously committed paedophilia, and they might place undue weight on that fact. They may even reach the conclusion that the defendant is guilty based upon that fact alone, which would undermine the concept of a fair trial.

Judges can direct juries to only consider tendency or coincidence evidence when making a determination about a particular issue, and can warn them not to place too much weight on such evidence.

But despite a judge’s directions, there are those who believe that no amount of ‘warning’ can reduce the prejudicial impact of some tendency or coincidence evidence, especially when it comes to cases of paedophilia.

Attaching too much weight to a person’s previous history is dangerous because it could lead to a wrongful conviction and to the ‘real’ offender escaping prosecution.


It should also be noted that if a person pleads guilty or is found guilty, the court will take their criminal record (if any) into account when deciding the appropriate punishment. This means that even if evidence of past conduct is not placed before the jury, it can certainly make the ultimate sentence harsher if the defendant is found guilty.

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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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