Can preventing or detecting crime be a defence to harassment?
Harassment is a course of conduct which amounts to harassment of another person and which they know, or ought to know, amounts to harassment. A typical harassment case will see an allegation that the defendant has contacted the complainant on multiple occasions or has published information – frequently on social media – about the complainant.
It is a defence to show that the course of conduct was done to prevent or detect crime. The defence is obviously intended primarily to protect police officers and other investigators from harassment allegations while doing their job. There is nothing in the Protection from Harassment Act 1997 that restricts the defence to the police. In this article, we will look at whether ordinary members of the public can rely on the defence.
The Supreme Court considered these defences in Hayes v Willoughby. Its decision is important whenever a defendant says that conduct which caused alarm or distress was intended to expose wrongdoing, protect potential victims or bring criminal behaviour to the attention of the authorities.
What does the law say?
Section 1 of the Protection from Harassment Act prohibits a course of conduct which amounts to harassment and which the person knows, or ought to know, amounts to harassment. A course of conduct requires behaviour on at least two occasions. Conduct includes speech, so letters, emails, messages and social media posts can all form part of the course of conduct.
Section 1(3)(a) provides that the prohibition does not apply if the person who pursued the course of conduct shows that it was done for the purpose of preventing or detecting crime. Comparable defences appear in the Act's more serious harassment and stalking offences.
Hayes v Willoughby: the case in brief
The first thing to note is that this is not a criminal case. It was a civil law case brought by Timothy Hayes against a former employee called Michael Willoughby under the Protection from Harassment Act 1997. It is relevant to criminal prosecutions though because it deals with exactly the same law and principles that is used to prosecute people in the criminal courts.
Mr Hayes managed several software businesses. Mr Willoughby had worked for one of those companies, and the two men fell out in 2002. Mr Willoughby came to believe that Mr Hayes had been involved in fraud, embezzlement and tax evasion. Over a number of years he sent a very large volume of correspondence to the Official Receiver, the police, the Department of Trade and Industry and other public bodies. The Official Receiver alone estimated that around 400 communications had passed between them.
The authorities investigated. They concluded that the allegations were unfounded and told Mr Willoughby so, with increasing firmness. He nevertheless continued. His campaign also extended into Mr Hayes's private life, including approaches to his former wife, his GP and his landlord. Mr Hayes brought a civil claim for damages and an injunction under the 1997 Act.
The trial judge found that the campaign amounted to harassment. He also found that Mr Willoughby sincerely believed his allegations and had subjectively directed his conduct towards detecting crime. At the beginning there had been a reasonable basis for suspicion. By June 2007, however, the crucial material had been examined and the Official Receiver had explained why it did not support the allegations. From then on, Mr Willoughby's persistence had become unreasonable and obsessive.
The trial judge nevertheless dismissed the claim because he treated the prevention or detection defence as entirely subjective: Mr Willoughby genuinely believed he was investigating crime. The case eventually worked its way to the Supreme Court where the Justices made some important observations about the law, its meaning and what is required to successfully argue the detection or prevention of crime defence.
Genuine belief is necessary, but it is not enough
Lord Sumption explained that the defence is not governed by an ordinary objective test of reasonableness. The defendant does not have to prove that a hypothetical reasonable person would have reached the same conclusion or chosen the same course of action. If that were the test, the separate defence in section 1(3)(c), which expressly protects conduct that is reasonable, would do much of the same work.
A wholly subjective test would create the opposite problem. A person with an absurd or obsessive belief could continue conduct which the law regards as oppressive simply by insisting that they were trying to detect crime. The Supreme Court therefore adopted a minimum test of rationality. The court examines the defendant's thinking, not merely the label the defendant gives to their conduct.
The defendant must have acted in good faith, applied their mind to material suggesting criminality and identified a logical connection between that material, the suspected crime and the conduct complained of. The conduct must also be capable of advancing the claimed purpose. This is a less demanding test than objective reasonableness, but it excludes arbitrary, capricious or perverse reasoning.
On the findings made at trial, Mr Willoughby could rely on the defence up until June 2007 but not afterwards because by that time the authorities had investigated and explained that there was no criminality.
What would a defendant need to show?
A genuine purpose of prevention or detection
The claimed purpose must be real. It is not necessary to prove that a crime was in fact committed, or that one was imminent. The question is why the defendant pursued the relevant course of conduct. A later explanation invented after arrest will carry less weight than messages, reports or decisions recorded at the time.
Detecting or preventing crime need not be the sole motivation
People often act for mixed reasons. The Supreme Court rejected the suggestion that preventing or detecting crime must be the only motive; it must be the dominant purpose. Anger, resentment or a personal interest does not automatically defeat the defence. However, threats, insults, humiliation or language about revenge may persuade a court that punishment or personal hostility was the real driving force for the defendant’s behaviour.
A rational evidential foundation
The defendant should be able to identify the information they believe indicates an offence, what the suspected offence and the reasoning which connected the two. Contemporaneous documents, screenshots, witness accounts, attempts to verify information and reports made to an appropriate authority may all help. The court is not deciding whether the defendant's conclusion was the best one. It is deciding whether the defendant genuinely reached it through a minimum rational process.
A logical connection between the action and the aim
The particular conduct must have been chosen because the defendant believed it would help prevent or detect crime, and that belief must itself be rational. The audience, wording, timing and repetition may therefore matter. A focused warning to people thought to be at risk will be easier to connect to prevention than a campaign directed at humiliating the subject before the widest possible audience. This is not a separate proportionality test, but those features can reveal the true purpose and whether the conduct could advance it.
A purpose that continued throughout the course of conduct
Hayes shows that a defence may apply at first and later fall away. A defendant must be able to explain how new information was assessed and why further action still served the claimed aim. Ignoring reliable contrary evidence, changing the allegation whenever one point is disproved or continuing after the objective can no longer be advanced may turn a rational investigation into unlawful harassment.
Social media warnings require particular care
The defence is not confined to reports made to the police. A private individual can rely on it, and in principle a social media warning may be intended to prevent crime by alerting potential victims. The court will, however, scrutinise whether warning others was genuinely the dominant purpose and whether the content, recipients and repetition had a rational relationship to that aim.
The later High Court decision in Hourani v Thomson illustrates the difficulty. A campaign publicly accused a man of murder, but the court found that the participants had not shown that preventing or detecting crime was their dominant purpose, or that their activities rationally served either purpose. Public denunciation of someone as already guilty is not the same thing as detecting an offence or preventing a future one.
Truth is relevant evidence, but it is not a free-standing defence to harassment. Nor does section 1(3)(a) authorise defamation, misuse of private information, unlawful disclosure of medical information, threatening communications or breach of a bail condition, injunction or restraining order. Each issue must be considered separately. Someone who is genuinely concerned about continuing offending should obtain advice before escalating or repeating a public campaign.
How Chetwode can help
These cases turn on purpose, reasoning and chronology. Early work should identify precisely which acts make up the alleged course of conduct, preserve the information available at each stage and explain why each step was taken. It may also be necessary to distinguish a genuine warning or report from material said to demonstrate hostility, obsession or an intention to punish.
If you are accused of harassment or stalking after reporting suspected crime or warning others about a perceived risk, Chetwode Criminal Defence Solicitors can assess the evidence, advise on the scope of the statutory defence and present the relevant context clearly. Taking advice promptly is especially important before making further contact or publication, because later conduct can affect how the whole course of behaviour is understood.