Royal Commission into Institutional Responses to Child Sexual Abuse chair Justice Peter McClellan will tell a lawyers conference on Friday that many of the most commonly held assumptions about child sexual abuse and sexual assault, and the criminal justice processes that have developed because of those assumptions, are not borne out by evidence.

“It appears that, although many more complainants are coming forward, the chances of an offender being acquitted have risen rather than fallen,” Justice McClellan will tell the Australian Lawyers Alliance NSW state conference, in a speech titled “Seeking ‘justice for victims’.”

“The question... is why do the outcomes for sexual assault differ so markedly from the outcomes for other crimes?”

Justice McClellan will outline key areas where reform is needed, including uniformity across Australian states and territories about the way courts deal with child sexual abuse cases to achieve consistency in outcomes.

“For survivors, and for many in the community, it may be difficult to understand why on some issues juries are directed in one way in one state, and differently in another,” he will say.

“If judges in New South Wales believe a rule is necessary to avoid an injustice, how is it that judges in Victoria do not?”

In a lengthy speech – the first of two to be presented to lawyers’ groups before a final report into criminal justice is provided to the Federal Government in August – Justice McClellan is critical of “judicial wisdom” about child sexual assault and sexual assault that has contributed to the criminal justice system creating “a series of barriers in sexual assault cases not known for other crimes”.

“Collective judicial ‘wisdom’ may be nothing more than the way we have always thought about the issue,” Justice McClellan will say.

The royal commission is considering changes to the law in relation to sexual offences by an offender against a child over the long term, after evidence that these victims are particularly disadvantaged in the criminal justice system.

“(It) is a cruel paradox: the greater the regularity with which a child is offended against, the more difficult it can become to charge and prosecute the offender,” Justice McClellan will say.

“It is unacceptable, in our view, that the criminal justice system should accept a situation in which children who have suffered the most extensive abuse may be those who are less able to receive justice in the criminal courts.” 

Barriers in the past included child sexual abuse and sexual abuse victims being classified as potentially unreliable witnesses and High Court decisions that had profound negative consequences for victims.

“They derive from what judges thought they knew about how genuine complainants behave and what they thought they knew about how memory works,” Justice McClellan will say.

“Those assumptions have turned out, with the benefit of empirical research, to be flawed. However, they became embedded in the fabric of the common law and proved difficult even for Parliament to dislodge.”

Relatively recent decisions where delays of six years in victims reporting sexual assault were described as “substantial”, were not only incorrect in light of royal commission findings that delays in reporting of more than 30 years were common, but their description as “substantial” could tend to “diminish the veracity of the allegation”.

Justice McClellan will tell the lawyers conference there was significant research demonstrating that the way a child behaves and reacts in response to child sexual abuse is inconsistent with the expectation of many jurors.

“It is important that research commissioned by the Commission demonstrates that defence counsel commonly use strategies when questioning complainants in child sexual abuse offence trials which rely on these misconceptions or uncertainties amongst jurors in relation to child complainants,” Justice McClellan will say. 

“Analysis of 120 transcripts of complainant evidence from 94 child sexual abuse trials showed that defence counsel often employed strategies to suggest that there is one typical way a victim responds to abuse.

“If the complainant had not responded in that way, counsel suggested to the jury that this was an indication that the offence may not have occurred.”

Research found that the types of misconceptions about child sexual abuse exploited included the lack of resistance by the complainant at the time of the offence, the delay in reporting, the apparent lack of emotion by the complainant at the time of the offence and the continued relationship between the complainant and the accused after the offence.

There was a strong case for juries to be given a consensus of expert opinion drawn from the work of psychiatrists, psychologists and other experts on child behaviour during trials. 

In his speech Justice McClellan will detail how concerns by some in the legal profession that the royal commission’s work had been so transformative that it disadvantaged offenders were not backed by evidence.

“In 2012-13 in NSW 73 child sexual assault matters were finalised, with the defendant convicted of all relevant offences in 29 per cent of matters, convicted of some but not all relevant offences in 27 per cent of matters, and convicted of no relevant offences in 44 per cent of matters,” Justice McClellan will say.

“By contrast, in 2015-2016, 142 matters were finalised at a defended hearing. That is almost double the number of matters. However, in relation to conviction rates the defendant was convicted of all relevant offences in 24 per cent of matters, convicted of some but not all relevant offences in 23 per cent of matters, and convicted of no relevant offences in 54 per cent of matters.

”It appears that, although many more complainants are coming forward, the chances of an offender being acquitted have risen rather than fallen.”

Justice McClellan’s second part of the speech will be delivered at the Modern Prosecutor Conference in Melbourne on April 13.