When somebody is accused of rape and found not guilty by the courts, it does not necessarily follow that the person who made the compliant lied.

There are all kinds of reasons why this might happen. The police may have got the wrong suspect. Eye-witness accounts vary and our memories – particularly if we have been traumatised – can be unreliable. In some cases, there is not enough evidence to convict – this is particularly true in date rape cases. Having listened to all the evidence, the jury might decide that there is reasonable doubt. Most of us believe it is better to let a possibly guilty person go free than send a potentially innocent person to jail.

Sometimes through no fault of their own, the victim is simply not believed, or makes a bad impression on the jury. Once again, traumatised people may not come across as coherent, leading the jury to doubt his or her word. In some cases, the jury may be prejudiced against the complainant – if you are working class, trans, a migrant, a minority or a sex worker you are less likely to be believed.

It is very hard to get a conviction in a rape case. This is one of the reasons why there is a widespread belief that many accusations of rape are false. It is commonly assumed that women cry rape for number of reasons – because they regret their sexual behaviour, want revenge or because they want attention. There is also a belief that innocent men are at the mercy of mendacious women who will ruin their reputations and have them sent to jail on a whim.

That’s not the case. A US study found that over a ten-year period only between 2 and 10 percent of accusations could be classified as “false.” The reason for the 8 percent gap is down to poor police procedures. If the victim decides not to co-operate with the police, makes inconsistent statements, was drunk at the time of the assault, or waits weeks, months or years before making a compliant, the police sometimes log these as false accusations. That doesn’t mean no rape happened or the accuser was lying.

Now before anyone starts screaming that the accused are “innocent until proven guilty” let’s admit that there are indeed cases where an accusation is false. It’s rare, but it does happen.

Studies have been done on false accusers and some interesting patterns have emerged. It seems that certain types of people are more likely than others to make a false claim of rape. The writer Sandra Newman did an analysis of these – and it is these people I want to talk about here.

The first and most prevalent group of false accusers are teenage girls. Teenage girls who get pregnant, get home late or get in trouble of some sort may try and deflect blame or punishment by claiming to have been raped.

These girls almost never report the false rape to the police. However their parents do. Two US studies found that around half of all false rape accusations made to police happen because someone else – not the fake victim – lodged a complaint, generally a parent. These cases rarely make it to court. Once the lie has served its purpose, the fake victim is unlikely to co-operate, or name a perpetrator.

There are however a handful of cases where adults pursue false rape claims through the criminal justice system. Interestingly enough, although false accusers are popularly assumed to be women, both men and women have been guilty of this.

There seems to be four motives for doing so – mental illness, personal gain, revenge or to establish an alibi.

One factor that is common amongst adult false accusers is a history of childhood sexual abuse. Because of this, false accusers with mental illness may truly believe they have been raped. Others have a personality disorder that is similar to Munchausen’s Syndrome and they generally have a history of making other types of false claims.

Adult false accusers motivated by personal gain are not always after money. In the United States, a large number of these false claims are made by people without medical insurance who need hospital care that they can’t afford. They don’t generally name a perpetrator as they are not interested in having anyone punished. However, those who are after money generally have a long history of making sketchy injury claims too.

Now let’s look at revenge. The cliché has it that “hell hath no fury like a woman scorned” – but it’s not true when it comes to false rape claims. Since 1989, 52 men convicted of rape have been exonerated according to the US National Registry of Exonerations – in the same period, 790 people were exonerated for murder. Of these 52 cases, none were convicted because of a scorned woman. A number of them featured accusers who traded sex for some gain, only for the person to renege on the agreement.

The last group comprises those who need an alibi. Like the largest group – teenage girls who use rape as an excuse – people in this group are trying to cover up something, for the most part infidelity. Like the lying teenage girls, these people don’t generally report a false attack to police either – someone else does so on their behalf, a partner or concerned friend.

The Los Angeles Police Department found that 78 percent of false rape claims were of aggravated assault. Fake victims rarely tell stories that involve date rape or could be the result of a misunderstanding between two drunk people. Instead they are more likely to claim that the perpetrator had a weapon, or that they were beaten or injured as well as raped.

We remember the big false accusation cases, such as the story of “Jackie” – the woman at the centre of the Rolling Stone “A Rape on Campus” controversy. Jackie falsely claimed she was gang-raped at a frat party at the University of Virginia. Before making this claim, she told a fellow student she was dying to elicit his sympathy.

Last year in the UK, Jemma Beale was jailed for ten years for making a series of false rape claims – four different incidents in three years, all accusing strangers.

Like Jackie, Jemma has a history of making false claims and also seems to have been trying to elicit sympathy from a former partner. In both cases, the women told stories of aggravated rapes – not date rapes, where consent might have been seen as ambiguous.

False accusers do great damage. Firstly, they do great harm to those they accuse. Beale had someone prosecuted and convicted – although it has since been overturned. They also make us assume that false accusations are more common than they really are. And they make it harder for real victims to come forward for fear that they will not be believed.

As awful as these women’s actions were, it is important to remember that they are outliers.
When someone you know or admire is accused of rape, you want to believe they are innocent. That’s human nature – we prefer to think the best of those we know.

When someone you know or admire claims to have been raped, you want to believe them too – and you probably should. The accused may be innocent until proven guilty, but if a woman or man claims to have been raped, statistically speaking at least, they are almost certainly telling the truth.