What caused the decrease in sexual assault clear-up rates?

Date: 26 Feb 2009

Click here for the full report (pdf, 465Kb)

Between 1995 and 2006, the proportion of sexual assault incidents recorded by the NSW Police Force as 'cleared' or 'partially cleared' within 360 days fell from 63 percent to 28 percent in 2006. Most of this fall occurred between 1995 and 2002. Clear up rates for sexual assault have been fairly steady since 2002.

The Bureau looked at three possible reasons for the decrease in clear-up rates:

1. Changes in the time taken by police to solve sexual assault crimes;

2. Changes in the police definition of what constitutes a 'cleared' sexual assault incident has changed; and

3. Changes in the number (and proportion) of cases where police lay criminal charges.

The Bureau found no evidence to support the first of these possibilities, very little evidence for the second but considerable evidence for the third.

In 2000, legal proceedings were initiated against a suspected offender in 26.6 per cent of sexual assault cases. By 2006, this had fallen to 15 per cent.

Several factors appear to have contributed to the drop in the number and proportion of cases where police are able to lay criminal charges.

Firstly, there has been an increase in the proportion of cases where the victim knows the offender. In fact there were twice as many cases in 2006 where the suspected offender was a current or former partner than there were in 2000.

Secondly, there has been an increase in the proportion of cases where the victim declines to give evidence against the accused person.

Thirdly, there were statistically significant falls in the proportions of incidents involving physical injury, weapon use and co-occurring offences.

Each of these factors has been shown to reduce the chances of prosecution and, therewith, the capacity of the police to clear the offence.

Commenting on the findings, the Director of the bureau, Dr Don Weatherburn, said that clear up rates for sexual assault are affected by a range of factors other than police performance.

"Most people think of sexual assault as an offence committed by predatory strangers".

"In nine out of 10 cases of sexual assault reported to NSW police, however, the victim and offender already know each other. In many cases they are partners or former partners".

The capacity of the police to lay charges and clear the offence in these circumstances depends greatly on whether the victim is willing to give evidence and whether there is any corroborating evidence, such as injury to the victim.

Our report suggests that the main reason for the decline in the clear up rate for sexual assault since the mid 1990s is a change in the profile of sexual assaults coming to the attention of police.

Further Enquiries: Dr Don Weatherburn 9231-9190, 0419-494-408.