Sex assault and rape: what the law says

We know little about what actually happened between four women and a former Liberal staffer at Parliament House. That is often the nature of these types of allegations. Witnesses are rare.

Four women have alleged they were sexually assaulted by the same political staffer. In at least two cases, the allegation is rape.

In another case, the allegation is of an undefined sexual assault. In the fourth case, the woman alleges that the former Liberal Party staffer reached under the table to stroke her thigh at a Canberra bar. Alcohol seems to have been involved in several of the situations. But, stepping back from these particular cases, what is the wider problem and what does the law say?

The robust evidence from a string of countries is that most rapes are committed by someone known to the victim, often in a home.

That is the case in Australia. Research by the Australian Institute of Family Studies and Victoria Police said: "According to the 2012 Personal Safety Survey, approximately 16 per cent of women (aged 18 and over) had experienced sexual offences by a known person, compared to five per cent by a stranger."

"In Australia, a greater proportion of females than males report experiencing sexual offences in the context of intimate partner relationships. Overall, 27,400 women reported experiencing sexual offences by their current partner at the time of the 2012 Personal Safety Survey. More than 250,000 women reported having been sexually offended against by a previous partner since the age of 15."

It's complicated because definitions vary across the states and territories.

New South Wales defines sexual assault in a way which the other territories define rape. NSW law says that someone is guilty of "sexual assault" when they have sex "without the consent of the other person" and when they know "that the other person does not consent to the sexual intercourse".

That definition meets the definition of rape in the rest of Australia. It's the same offence. In the ACT, rape can be when the person is "reckless as to whether that other person consents".

All jurisdictions agree that the crime of rape involves penetration.

With the exception of New South Wales, sexual assault is an indecent assault (unwanted and sexual) but without penetration. The seriousness of the assault necessary for it to be a crime is not defined in law.

According to the Australian Institute of Health and Welfare, "Sexual assault is a type of sexual violence that involves any physical contact, or intent of contact, of a sexual nature against a person's will, using physical force, intimidation or coercion.

"It can be aggravated in nature (including rape, attempted rape, sexual assault with a weapon, indecent assault, penetration by objects, forced sexual activity that did not end in penetration, attempts to force a person into sexual activity) or non-aggravated in nature."

Consent forms a central aspect to many sexual assault cases. Does consent to sex when drunk count as true consent? What if the two people work together and one has power over the other?

It should be said that innocence of crime before a jury may still not mean acceptable behaviour in work.

But on the law, Dr Nicola Henry of the RMIT University told this paper: "Consent is generally defined as 'free and voluntary agreement'."

Consent "requires both parties to take active steps to find out if the other person is consenting. This might include asking the other person if they want to have sex, or if they are OK to continue."

Consent cannot be "inferred".

"Although the affirmative standard of consent is not mentioned in some Australian state and territory laws, in others it is. In Tasmania, for instance, the accused person must have taken 'reasonable steps in the circumstances' to find out if the other person was consenting."

And consent once doesn't mean consent the next time. Also, Dr Henry says, "Just because someone consented to engage in one sexual or intimate act with you on a particular occasion (for example, kissing or foreplay) does not mean that they consented to another sexual act with you (for example, intercourse)."

Dr Henry says: "In some Australian states and territories, consent cannot be given if the person is significantly impacted by alcohol or other drugs to the extent that they cannot be said to 'freely agree' to the sexual activity. The degree to which the intoxication renders a person unable to consent is a matter for the jury and is not clear cut."

Dr Henry says: if in doubt, err on the side of caution. Consensual sex is possible under the influence of drugs, including alcohol, but "if they are affected by drugs or alcohol to a substantial degree (for example, they cannot stand up or walk), then they cannot be considered to be freely or voluntarily consenting".

Assuming consent, does the power of one over the other at work matter?

Dr Henry says: "Under Australian law, it is not a criminal offence for two consenting adults to engage in sexual activity, even if one of the parties is in a position of power. However, it may be against workplace policies and practices."