Citizens Unmuzzled: Citizens’ Arrests and Other Powers in Animal Welfare Cases

Updated: May 26

In certain circumstances, powers of arrest are exercisable not just by police officers but by ordinary citizens, similarly conduct that might otherwise be unlawful can become lawful. Samuel March, a Barrister at 9 King’s Bench Walk and a volunteer paralegal at Advocates for Animals, examines what powers ordinary people have to intervene in animal abuse cases, and in particular a perhaps unforeseen consequence of the recent Animal Welfare (Sentencing) Act 2021

For animal advocates, seeing an animal suffering or being abused is likely to foster a powerful urge to intervene. Seeing any crime in progress sparks fight or flight reflexes, events can play out in a matter of seconds, and witnesses don’t always have time to call the police, still less seek legal advice or research their powers. This makes knowing what to do difficult, because citizens’ powers to arrest or otherwise intervene are incredibly fact specific and involve striking delicate balances in these split-second decisions. This article is not intended as legal advice or a comprehensive guide, but as a top-level overview of some of the key powers ordinary people may have, in certain limited circumstances, to step into a situation and stand up for animals


There is no definitive legal definition for what constitutes an “arrest”. It is not defined by the Police and Criminal Evidence Act 1984 or indeed any other legislation, and the caselaw is not entirely consistent. Nevertheless, a broad definition was given in the case of Spicer v. Holt [1977] A.C. 987 at p1000:

“ ‘Arrest’ is an ordinary English word … Whether or not a person has been arrested depends not on the legality of the arrest but on whether he has been deprived of his liberty to go where he pleases.”

Adding to this in, it was held in Mohammed-Holgate v. Duke [1984] A.C. 437 at p441 that

“arrest is a continuing act; it starts with the arrester taking a person into his custody, (sc. by action or words restraining him from moving anywhere beyond the arrester's control), and it continues until the person so restrained is either released from custody or, having been brought before a magistrate, is remanded in custody by the magistrate's judicial act.”

The vast majority of arrests are executed by trained police officers, using specific powers of arrest that apply only to them. However, neither a warrant nor rank are always prerequisites for arresting a suspect.

As of the 29 June 2021, a bystander who witnesses someone mistreating their dog in the park may, in some circumstances, have the power to perform a citizen’s arrest. The conditions in which “a person other than a constable” may arrest without a warrant are set out at s.24A Police and Criminal Evidence Act 1984.

Essentially, there must be “grounds” for the arrest and the arrest, the arrest must be “necessary” for one of a limited number of reasons. Furthermore, the arrest will only be lawful if it appears to the person making the arrest that it is not reasonably practicable for a constable to make it instead.

Ground for arrest in animal welfare cases

The first condition is that there must be grounds for the arrest. In this context, that means at the time of the arrest the suspect must have committed or must be committing an indictable offence; or the person arresting must have reasonable grounds to suspect that the suspect has committed or is committing an offence.

A couple of important takeaways about grounds for arrest: the first is that, unlike police officers’ powers, the citizen’s arrest powers do NOT cover situations in which a suspect is (or is reasonably believed) to be about to commit an offence. It applies only to offences that have already or are currently being committed.

The second takeaway, and one that is easily lost on the non-lawyer, is that unlike a police officer who can arrest a suspect for any type of offence, citizens can only perform an arrest on suspicion of an “indictable” offence. Under the law of England and Wales, offences can be grouped into two categories depending on their “mode of trial”: summary offences (which are tried in the magistrates’ courts) and indictable offences (which can be tried in the Crown Court).

If an offence is a summary only offence (such as speeding), then the citizen’s arrest powers do not apply. This makes the decision to attempt a citizen’s arrest tricky. Even lawyers sometimes have to double check their textbooks to see whether a particular offence can be tried on indictment in the Crown Court or not. Citizen’s arrest powers therefore need to be exercised with great caution and are particularly risky unless confident of mode of trial of the offence in question. Given that citizen’s arrest powers are really intended to cover situations where a crime is ongoing, playing out second by second or just concluded, an ordinary citizen may struggle to check such procedural technicalities. Get the mode of trial wrong, and the arrester risks themselves being guilty of a criminal offence against the person, or liable for damages for trespass against the person (although see the broader powers below).

What is particularly interesting in the context of animal welfare is that, until recently, the main animal welfare offences were all summary only offences. This would mean that if you were in the park and witnessed someone causing unnecessary suffering to an animal contrary to s.4 Animal Welfare Act 2006 (“the 2006 Act”), only a police officer would have the power to arrest them.

That position changed last year with the introduction of the Animal Welfare (Sentencing) Act 2021 (“the 2021 Act”). The primary intention of the 2021 Act was to increase the maximum penalty for a small number of animal offences (causing unnecessary suffering, mutilation, docking of dogs’ tails, administration of poisons etc and fighting etc) from 6 months to 5 years.

In order to do this, the 2021 Act had to turn these offences from summary only offences to indictable offences, because only the Crown Court can impose such lengthy custodial sentences. This means that, as a potentially unintended consequence, some of the main animal welfare offences can now give rise to lawful grounds for a citizen’s arrest.

A word of warning: even with the introduction of the 2021 Act, some animal welfare offences remain summary only offences. So whilst causing unnecessary suffering contrary to s.4 of the 2006 Act could give rise to grounds for a citizen’s arrest, an breach of s.9 (duty of person responsible for animal to ensure welfare) would not be sufficient. It is beyond the scope of this article to try and detail each of the elements of each of these offences or provide a comprehensive list of animal offences by mode of trial. It is stressed again that citizens’ arrests engage a multitude of legal technicalities, and a great deal of caution is required to avoid criminal and/or civil liability.

Necessity for arrest

Grounds alone do not empower any person on the street to arrest a suspect. The person making the arrest must also have reasonable grounds for believing that the arrest is “necessary” for one of four reasons specified in s.24A(4). According to that subsection, a citizen’s arrest must be necessary to prevent the suspect from

“(a)causing physical injury to himself or any other person;

(b)suffering physical injury;

(c)causing loss of or damage to property; or

(d)making off before a constable can assume responsibility for him.”

These reasons are exhaustive. They curtail in important ways the situations in which it might be legal to perform a citizen’s arrest in an animal welfare case. There will be some animal abuse cases concerning animals capable of responding aggressively; in which subsections (a) or (b) may be engaged. However, it is important to note that - unlike in some more progressive jurisdictions - no court in England and Wales has yet held that a non-human animal is a legal “person”. So unlike cases in which an indictable offence against a child is witnessed, the limb concerning preventing “physical injury to […] any […] person” does not apply when stepping in to safeguard an animal.

Whilst animals are not legal “persons”, they can be legal “property”, and so subsection (c) is more likely to be relevant in cases where companion or farmed animals are abused. Interestingly, the statute does not explicitly specify that the property must belong to someone other than the suspect, and it may raise an interesting (and to the author’s knowledge as of yet undecided) question of law if an animal advocate were to perform a citizen’s arrest on a suspect to prevent the suspect damaging his or her own companion or farmed animal.

In many cases, the most appropriate limb will be subsection (d). If a suspect is challenged and informed that the police are being called, and then goes to make off, it may be appropriate to detain them if there is no other way of obtaining their identity or address for the police.

Subsection 4(d) ties in closely with subsection 3(b) which species that citizen’s arrest powers are exercisable ONLY if

“(b)it appears to the person making the arrest that it is not reasonably practicable for a constable to make it instead”

The lesson here is that if it is practicable to call the police, then that must be the first port of call. It will generally only be appropriate for a citizen to make the arrest if there is a degree of urgency that renders this impracticable, because of risk to people or property detailed above, or to prevent escape. It is a limited and technical power; not a broad-brush permission for vigilante justice.


This article has focussed primarily on citizens’ arrests, due to the interesting technical change that the 2021 Act appears to have brought about.

However, given how narrow and technical the power to execute a citizen’s arrest is, it bears mentioning that there is a broader power under s.3 of the Criminal Law Act which provides that a person (any person) “may use such force as is reasonable in the circumstances in the prevention of crime”. Unlike the citizen’s arrest powers, this power may apply where a person honestly believes that a crime is about to be committed, so long as they use no more force than is reasonable to prevent it.

This is a much less technical power, and what is considered “reasonable in the circumstances” will always hang on the specific facts of a given case. What is “reasonable” is an “objective” test, meaning it is not about whether the person themselves believed that what they were doing was reasonable, but whether a hypothetical ordinary and fair-minded person would consider the degree of force used was reasonable in the circumstances.

This is, therefore, also a power to be exercised with great caution and restraint, because different tribunals (different judges, magistrates or juries) may take very different views about what is reasonable in a given situation. It may be that a passionate animal advocate would honestly believe that it was acceptable to use a great deal of force to save a suffering animal from unlawful harm, but a tribunal might take the view that it would rarely be appropriate to lay a finger on a human in order to save a factory farmed chicken, even if they were being mistreated. Sadly, lawyers working on animal cases will all have experienced cases in which courts have given human interests exponentially more weight than animal interests.


Whilst some powers to intervene are broad, others apply only as defences to specific offences. To discuss all offence-specific offences is beyond the scope of this article, but one example frequently raised in animal cases is the question of when preventing animal suffering can render lawful behaviour that would otherwise constitute criminal damage.

The basic offence of destroying or damaging property is set out at s.1(1) Criminal Damage Act 1971. It is a crime for a person “without lawful excuse” to destroy or damage any property belonging to another intending to destroy or damage any such property, or being reckless as to whether any such property would be destroyed or damaged.

In ordinary circumstances this would include breaking the window to someone else’s car, but a possible exception to this might be if, on a hot day, all the car doors and windows were closed, and the car owner had left a dog inside. According to the RSPCA, even when it's only a pleasant 22 degrees Celsius outside, the car could reach an unbearable 47 degrees within an hour. It is not uncommon to hear of dogs dying in such conditions.

The question then arises of whether it is lawful to break the window to rescue the dog. Again, this will always be case specific and there is no general right answer. The first step clearly is to assess the dog’s condition. Even if the dog is showing signs of heatstroke, the safest course of action legally is generally to call the police and see how long it would take officers to attend.

However, it may not always be possible for officers to get there in time. There may be limited circumstances in which it would be appropriate to break a window.

The term “without lawful excuse” is expanded on in s.5 of the Criminal Damage Act 1971 and includes some non-exhaustive examples of lawful excuses that could potentially serve as a defence to a person accused of criminal damage in this scenario.

The first is if the accused believed the owner of the car would consent if they knew about the circumstances. Depending on the state of the dog, one might well believe that a car owner would rather have their window smashed than allow their dog to die.

The second is if the accused breaks the window in order to protect property (as explained above dogs are legally property) belonging to himself or another (which could include the car owner) and he believed that the property was in immediate need of protection and the means adopted were reasonable having regard to all the circumstances.


The instinct of many an animal advocate, on seeing an animal being mistreated, may be to seek to take the law into their own hands, intervene and take the animal away from the person mistreating it, even if the abuser is the legal owner of the animal. There is no clear statutory power of “citizen’s seizure” equivalent to the power to effect an arrest. So, whilst it may be lawful to intervene in some circumstances, for the average citizen to attempt to do so is potentially to stray into a legal minefield.

Because companion and farmed animals are property, ordinary citizens attempting to seize an animal on welfare grounds could potentially lead to them finding themselves facing criminal proceedings for theft or, in the future if the Animal Welfare (Kept Animals) Bill is enacted, the new proposed “taking of pets” offence. The offence of theft has, in the past, been used to prosecute animal activists involved in appropriating (generally with the intention of freeing or re-homing) animals from laboratories or farms. That being said, s.1 of the Theft Act 1968 makes it clear that taking someone else’s property is not theft unless the prosecution proves beyond reasonable doubt that the accused was both “dishonest” and had the “intention to permanently deprive” another of their property. If the court believed that a defendant was (or may be) only temporarily removing the animal, then theft would not be made out. Similarly, depending on the nature of the abuse witnessed, the court might take the view that there was no dishonesty involved.

Unlike theft, the new “taking of pets” offence set out at s.43 Animal Welfare (Kept Animals) Bill, if enacted, would require neither dishonesty nor intention to permanently deprive. Subject to a few quite technical exceptions, a person would commit an offence if, without lawful authority or reasonable excuse, that person took or detained a dog (the proposed bill applies only to dogs) in England so as to remove it from the lawful control of any person, or so as to keep it from the lawful control of a person who is entitled to have lawful control of it. The key issue in this case would be “reasonable excuse”. Once more, each case would turn heavily on its own facts, the quality of the evidence, and different tribunals’ assessments of what is “reasonable” in the circumstances.

Even if criminal liability can be escaped, the intervener runs the risk of being sued in a civil court for the tort (civil wrong) of “conversion” (which is broadly concerned with excluding the legal owner from access to their own property), or “trespass to goods” (which is generally concerned with more minor interference with goods). Because animals are considered “chattels”, “goods” or “property”, they fall within the ambit of 'wrongful interference with goods' for the purpose of the Torts (Interference with Goods) Act 1977.

That being said, there is a general principle in tort law that claimants cannot recover where their loss occurred while they were engaged in serious wrongdoing. This is often referred to by the Latin maxim ex turpi causa non oritur action: no cause of action arises from illegal or flagrantly immoral acts. This maxim does not, it should be stressed, mean that the mere fact that a claimant was involved in immoral or criminal conduct will be an absolute barrier to any claim. Whether or not an animal abuser has an action against someone who remove the animal from him would come down to the court’s assessment of various factors including how reprehensible the treatment of the animal was and whether it is proportionate to deprive the owner of a civil remedy (see cases such as Joyce v O’Brien [2012] EWHC 1324 (QB) and Cross v Kirkby [2000] EWCA Civ 426.)

As ever, before taking the law into one’s own hands the safest course is always ask first whether it is practicable to call the authorities instead. Under the S.18 of the Animal Welfare Act, constables or inspectors who reasonably believe that an animal is suffering have certain powers to take, or arrange the taking of, such steps as appear to be immediately necessary to alleviate the animal's suffering. This can involve, if certain criteria are met, taking the animal into a place of safety, arranging care for it or if necessary, putting the animal down to end its suffering. These authorities only apply to officers or inspectors, not ordinary citizens, and many of the powers under the 2006 Act require a certificate from a veterinary surgeon. Given the express powers bestowed on constables and inspectors, it will seldom be appropriate for a citizen to intervene unless the urgencies of the situation make it impracticable to call the police.


In appropriate cases, it may be perfectly legal for ordinary people to step in and stand up for an animal in distress, even if this means using force, but it is not something to be undertaken lightly. Every case turns closely on its own facts and questions of “necessity” and “reasonableness”, although supposedly “objective” tests, can mean different things to different people. As a result, it is generally risky to use force against people or property, because even slightly misjudging the circumstances can lead to someone with good intentions having to justify, and potentially be punished for, their actions in court. This piece has focussed on the legal risks and has not touched on the general safety risk that suspects very often fight back. There are many reasons that the use of force is, where possible, safer to leave to officers with appropriate training and the authority and resources of the state to fall back on.

Getting Advice

This blog post is not legal advice. If you’re an animal advocate, organisation or charity and concerned about the issues raised in this post, it is vital to seek expert advice at the earliest possible stage. This will help maximise your chances of staying on the right side of the law. For more information on the services Advocates for Animals offers please contact

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