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What is Self-Defence?


What is Self-Defence?

All too often I have heard various misconceptions about the term ‘self-defence’ and what does and does not constitute a legally accurate and a fit for purpose description of this term.  I have heard people at one extreme say “He hit me first so I hit him back; it’s self-defence” through to the other extreme of “You can’t do anything by law if a pupil attacks you or it will be assault against a child”. Both of these extremes are incorrect and incredibly dangerous for varying reasons as you will soon find out.

I aim to not only explain what self-defence is but also give you the tools with which to look at other instances of self-defence or use of force so you can judge for yourself if the force was legitimate or assault.  Before we look at these examples, we first need to understand what ‘self-defence’ actually is and if indeed, we are allowed by law to defend ourselves.

Well, quite obviously we are all allowed to defend ourselves when faced with an attacker or violent situation and this is provided by Common Law. ‘The lawyers’ practitioner’s text (Archbold 19-41)’ states:

“It is both good law and good sense that a man who is attacked may defend himself. It is both good law and good sense that he may do, but only do, what is reasonably necessary.”

At COVIC Training Solutions we use this definition when teaching self-defence:

“The defensive use of physical force for the purpose of preventing an actual or imminent threat of unlawful violence against the person with the aim of creating a window of opportunity to escape the threat”

Section 3 Criminal Law Act 1967 states:

“A person may use such force as is reasonable in the circumstances in the prevention of crime, or in effecting or assisting in the lawful arrest of offenders or suspected offenders or of persons unlawfully at large.”

Ok, that’s great! The law has said we can defend ourselves, but what do ‘reasonably necessary’ and ‘reasonable force’ actually mean? Well, let’s see what the courts say. In assessing the reasonableness of the force used, prosecutors generally ask two questions:

  •   Was the use of force necessary in the circumstances, i.e. was there a need for any force at all?


  • Was the force used reasonable in the circumstances?

The courts have indicated that both questions are to answered on the basis of the facts as the accused honestly believed them to be (R v Williams (G) 78 Cr App R 276), (R. v Oatbridge, 94 Cr App R 367).

If we look at those questions individually, the important part of the first question is the word ‘necessary’. In other words, was force the only option the defendant had to ensure their own safety? Could they have withdrawn from the area? Could they have resolved the situation with effective communication? Was their only exit blocked? How violent or aggressive was the assailant?

If a person has no other option but to use force to ensure their own safety, in the circumstances as they see them at that point in time, there is a very strong case for force to have been necessary.

Ok, so what is reasonable force, as mentioned in Section 3 Criminal Law Act 1967? ‘Reasonable’ is a bit of a subjective words isn’t it? What is reasonable for one person could be very different for another. Well, quite frankly yes it is, very subjective, however there is a simple way of clarifying what is reasonable force.

One must look at the level of damage or injury that would likely have occurred if force was not used, and balance it against the damage or injury caused in the prevention of that crime.
For instance, I’m about to be assaulted by a man of similar build and weight to my own without any weapons. If I pick up an iron bar and hit him over the head with it, this is excessive force. The damage he is likely to do to me if I don’t use force doesn’t compare to the damage I would do to him by using an iron bar. The force is disproportionate. I am risking his life when there is little or no threat to my own.

If, however, he pulls a knife out and I genuinely believe he is going to use it and my life is in imminent danger, is it potentially proportionate in this instance to use an iron bar in my own defence? My life is in danger from the knife. I could feasibly kill my attacker with the iron bar, but if I don’t do something I could well end up being stabbed and being killed. With the latter example, it would be much easier to claim self-defence as there is risk to my life if I do not act, balanced against the risk to the assailant’s life if I do.

The threat level to me at this level is significant. Consider how much higher would the threat level be if I were a young female, 5’6”, weighing approximately 9st and my attacker was a mid-40’s male, 6’2” and weighing approximately 16st? Would it be reasonable to expect the female to wait for a knife to be pulled before using an iron bar? It could be argued that due to the massive difference in size, weight and strength that the female could use much higher levels of force when protecting herself due to the increased level of potential damage if she sustained any blows.

When discussing reasonable force, I like to use simple formula like this:

Necessary + Proportionate = Reasonable

Life threatening and highly severe self-defence is provided by law but only if it can be suitably justified and proved that without prejudice, the action taken was the only option available at that time. This level of force can only be employed when absolutely necessary and must be strictly proportionate:

“…. where a forcible and violent felony is attempted upon the person of another, the party assaulted, or his servant, or any other person present, is entitled to repel force by force, and, if necessary, to kill the aggressor ….”.

Chisam (1963) 47 Cr App Rep 130

If we refer back to the example where I’m being threatened by an armed man, my life is in danger but I can’t just take the attackers life. I do have other options. I have an iron bar but I can strike the attackers arm, breaking it and making him drop the knife. The force is proportionate but I’ve not taken the attacker’s life and the level of force used is more easily defensible.

“If there has been an attack so that the defence is reasonably necessary, it will be recognised that a person defending himself cannot weigh to a nicety the exact measure of his necessary defensive action. If a jury thought that in a moment of unexpected anguish a person attacked had only done what he honestly and instinctively thought was necessary that would be most potent evidence that only reasonable defensive action had been taken.”

Palmer [1971] AC 814 (Privy Council) Lord Morris
That last quote basically means that in some instances the defendant can’t be expected by the court to have weighed up and thought through every option available before acting in self-defence. This provides for genuine cases where excessive force is used by the defendant, but the circumstances of the incident prevented the defendant from being able to weigh up all options. The key to this again is justification of actions by demonstrating the level of perceived threat.

So when we look at the first examples of people’s perceptions of self-defence again, we can see that both extremes are incredibly flawed. Recently there was a case of a Police Officer assaulting a prisoner for spitting in his mouth, claiming that he thought the prisoner was going to spit again. The questions I would ask are:

  • ‘Why didn’t you step back out of spitting range?’
  • ‘Was the act of striking the prisoner in the face, causing enough damage to create a pool of blood in the van proportionate in damage or injury to a being spat in the face?’

Using the formula above we can see that force was not necessary as the Officer could possibly have backed out of spitting distance. Was the punch to the face proportionate? No, of course it wasn’t. I have no doubt the Officer was quite rightly angry at the prisoner, but this isn’t suitable reason to use that level of force. This action is more commonly known as retaliation or revenge; not self-defence. A link to the article is here:
Policeman Guilty of Assaulting Spitting Suspect

So when does genuine self-defence become assault? Can it become assault? Well, in short, yes it can. We only have a legal right to use force against another while there is a genuine perceived threat to our safety. Once that threat has gone or has been eliminated, we no longer have the right to use force. Similarly, the level of force one can use will differ in relation to the presented threat.

For instance, if I’m being threatened by a man with a knife and I genuinely fear he is going to kill me, I am well within my rights to use enough force to remove that threat. That isn’t necessarily strike him with the iron bar on the head as previously mentioned. I could instead strike him on the arm that is carrying the blade. Would that not eliminate the threat of being stabbed as he drops the knife? He may well suffer a broken arm, but the threat of being stabbed has now been eliminated.

If I then begin to attack him further with the iron bar, I now become the aggressor. This is because the threat level to me is now greatly diminished, but the level of damage I would cause is disproportionately higher making the level of force illegal and therefore assault. When using force we must always reduce the level of force in line with the reduction of perceived threat.

So, in summary; yes we can defend ourselves provided the force is necessary and the force is proportionate to the damage or injury likely to be sustained if we don’t act, regardless of gender, age or any other demographic. As long as there is a threat to our safety, we are able to use proportionate force to eliminate that threat. Once the threat has been negated, force is no longer an available option.

I hope this helps to clear up any misunderstanding surrounding what ‘self-defence’ actually means in law. If you would to discuss this further then by all means send me a message.

Colin Vowles

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