'It is better that ten guilty persons escape than that one innocent suffer'.

These words of 18th century English jurist William Blackstone resonate just as loudly today as they did back then in relation to the magnitude of the injustice created by imprisoning innocent people.

But what do we know about the causes of wrongful convictions in Australia, and what can be done to achieve justice for innocent people who are languishing behind bars?

What is a wrongful conviction?

A 'wrongful conviction' occurs when a person is convicted of crime they did not commit.

Such convictions amount to a 'miscarriage of justice', although that term encompasses a far broader range of circumstances than just a wrongful conviction, including the absence of a fair trial and the admission of unfairly prejudicial evidence.

Can the percentage of wrongful convictions be estimated?

The short answer is no – it is impossible to give a realistic estimate of innocent people who are convicted, despite various researchers in the United States and other nations attempting to do so.

This is due to a range of factors, not the least of which is that many wrongful convictions will never come to light, with those sentenced to imprisonment languishing behind bars despite their innocence.

Other factors are that people who are innocent may nevertheless plead guilty – whether to the charges they are facing or to downgraded charges – in order to avoid the risk of a lengthier conviction after a hearing or trial.

Some defendants may be pressured into pleading guilty by their lawyers or as a result of their inability to afford a lengthy hearing or trial. Others may simply wish to 'get it over with' and avoid a trial and all the associated stress, anxiety, delay and uncertainty it causes to themselves and their families.

Others may fall victim of inadequate legal representation during the hearing or trial, or the admission of false or mistaken evidence such as notoriously unreliable identification evidence.

So it is not sensible or realistic to estimate the number or percentage of people convicted despite the fact that they are innocent.

Notable cases of wrongful convictions in Australia

That said, there are at least seventy high-profile, reported cases of wrongful convictions in Australia, from Lindsay Chamberlain, to the Mickelberg brothers, John Button and Andrew Mallard – all of whom were eventually released from prison (except Peter Mickelberg who died behind bars) after it became clear they should not have been convicted in the first place.

Causes of Wrongful Conviction

While the reasons for wrongful convictions are often complex and multi-faceted, the research of Professors Juliette Langdon and Paul Wilson into reported cases in the United States suggests that:

  • 50% were signified by over-zealous and/or unprofessional police investigations,
  • 44% were based on profiling and weak circumstantial evidence,
  • 22% of cases exhibited incompetence in the investigation, with 12.5% of those involving criminal conduct by police, and
  • 22% involved discredited expert evidence.

The researchers found that a single focus, or 'tunnel vision' in the investigation process led to innocent people being convicted.

Professors Keith Findley and Michael S Scott from the University of Wisconsin similarly found tunnel vision to be a significant contributing factor, describing it as where investigators "focus on a suspect, select and filter the evidence that will 'build a case' for conviction, while ignoring the suppressing evidence that points away from guilt".

However, unreliable evidence such as identification evidence – especially where it relates to the identification of minority groups – and the misleading presentation of forensic evidence have also been identified as significant contributing factors.

Indeed, the majority of the more than 300 people exonerated through the Innocence Project in the United States were set free after they were convicted solely or primarily on identification evidence, when DNA evidence from the crime scene later established they were not the perpetrators.

Some of these people spent decades behind bars before their release, and a number were on death row.

What can be done?

On a broad level, it is fundamental that the law maintains the presumption of innocence – which is a fundamental principle that has been significantly curtailed by successive state and federal governments in Australia.

The right to a lawyer in criminal cases – something which is guaranteed throughout the United States but not in Australia – is also important in ensuring that defendants are not left to represent themselves against a well-funded, professional prosecution, and do not feel compelled to plead guilty for financial reasons.

The United States has a robust Innocence Project which reviews selected cases of alleged wrongful imprisonment. And while there are small Innocence Projects in Australia, they have nowhere near the same resources.

Funding Innocence Projects could provide an avenue for those who have been wrongly convicted and exhausted their regular avenues of appeal to achieve justice.

England, Wales and Northern Ireland have a Criminal Cases Review Commission (CCRC) whose role is to review the cases of alleged wrongful convictions, investigate them and, where appropriate, act to ensure justice.

A similar body in Australia would also assist in promoting justice for those who have been wrongly convicted and exhausted their appeals.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.