Most sexual assaults are not reported to authorities, new data on the ACT suggests, but police have assured the public they have "a powerful suite of appropriate tools" to investigate such offences when reported.
The Australian Bureau of Statistics has released new analysis of its 2016 personal safety survey, which estimates 1800 ACT women experienced sexual assault in the year prior to completing the survey. An estimated 100 more women experienced sexual threats.
ACT Policing's crime statistics, published quarterly, reveal an annual average of 478 sexual assault reports between 2014 and 2018. The police statistics are not broken down by gender.
Women's Centre for Health Matters deputy chief executive Emma Davidson said women often decided not to report sexual assaults because they did not believe doing so would bring them justice.
She said people also tended to look beyond the offender to find a reason that would explain the crime.
"People talking about, 'Why were you drinking?' 'Why were you out after dark?' 'Why did you choose to be in a room alone with that person?' That's just not helpful [for victims]," Ms Davidson said.
"The fundamental problem is that the people who are committing those crimes need to stop committing those crimes.
"When women have experienced violence, we should never be asking them about their behaviour. We should be asking the people who committed those crimes, 'Why did you choose to do this to that person?'"
Ms Davidson said many Canberra women had expressed fears for their safety when they went to certain areas after dark.
She said this meant those women had to risk feeling unsafe or miss out on things like going on a night out, attending community meetings and playing sport.
An ACT Policing spokeswoman said a person's decision to report a sexual assault could be influenced by a range of factors including a sense of guilt, family pressure or expectations, personal shame or embarrassment and a desire to move on and put the incident behind them.
"ACT Policing works closely with victims to ensure that their voice is heard and respected," the spokeswoman said.
"The wishes of victims play a pivotal role in determining whether [sexual] offences are progressed to the courts."
The spokeswoman said when ACT Policing's sexual assault and child abuse team received a report, it worked with the forensic and medical sexual assault care unit, Canberra Rape Crisis Centre and other support services to support victims.
She said it was not uncommon for victims of sexual offences to take many years to report the offending.
"Victims always have the say in how far a police investigation goes, can determine that a matter not proceed to prosecution, and can withdraw from the process at any time," the spokeswoman said.
"It is not uncommon for an investigation to halt, not proceed to prosecution, or to be recommenced at a later time, at the request of a victim.
"It is important that a victim has the say in whether a matter proceeds to public airing in court, and police are committed to ensuring that victims have a voice."
To reduce the need for victims to revisit painful memories in court, police are able to record "evidence-in-chief" interviews, allowing victims to provide their evidence in a safe environment before court proceedings began.
These powerful evidence provisions also extend to violence and family violence offences.
The ACT Policing spokeswoman said this was about "providing our courts with the best evidence and empowering victims".
"The ACT community can rest assured that police have a powerful suite of appropriate tools at their disposal to investigate such offences when reported," she said.
Canberra Rape Crisis Centre chief executive Chrystina Stanford was contacted for comment.