Necessity A second requirement for justification on the basis of self-defense is that
the defense must be a capable and necessary means to repel the attack. The use of
force in self-defense seems to be only necessary when there are no reasonable
alternatives, such as firing a warning shot into the air. Generally speaking, this also
implies that if there is a possibility to retreat or to get help, one should use it.
Imagine a situation where John is attacked at his door by his angry neighbor. Instead of
hitting his aggressor, he should simply close the door.Proportionality This third requirement assesses the relationship between the
offense committed and the amount of harm likely to be suffered by the defendant
if he had not intervened with force. It is about weighing the interests of the
aggressor against those of the defendant. In principle, the least intrusive means
that are still effective should be chosen, taking into account all the circumstances,
such as the nature of the force used and the seriousness of the evil to be prevented.
The person who shoots dead a pickpocket who just took his wallet can normally not invoke
justified self-defense because shooting the pickpocket dead is not proportional to stealing a
wallet.
It is however not required that the defensive force must be exactly in proportion
with the attack. As long as the force used was not adisproportionateresponse to the
attack, the defendant will be justified. This can be grounded in the reproach that can
be made against the aggressor and because the defendant cannot be expected to
make a perfect weighing of interests in an urgent situation.
7.7.2 Insanity
The most popular excuse is insanity. Article 39 of the Dutch Criminal Code gives a
good illustration of this defense:
He who commits an act for which he cannot be held responsible by reason of a defective
development or medical disorder of his mental capacities is not criminally liable.Rationale of the Defense The main rationale of the insanity defense is that it
guarantees that those who are not responsible for their actions are not punishable. In
all legal systems, the insane defendant will therefore be compulsorily admitted to
and/or treated in a mental hospital. By framing insanity as an excuse, the state may
impose measures upon these perpetrators of wrongful acts. As long as the danger
remains and treatment is necessary, the defendant can be detained in a mental
hospital. This brings about the fact that by pleading an insanity defense, the
defendant risks to be deprived of his freedom for an indefinite time. Not surpris-
ingly, most defendants view these measures as a punishment worse than prison.
Requirements The conditions of an insanity defense essentially require that the
offense should be attributable to the mental disorder. This means that, first of all, it
needs to be established that the defendant was suffering from a relevant mental
7 Criminal Law 141