Self-Defence, Necessity, and Duress

• Author: Kent Roach
• Pages: 367-440

367

CHA PTER 9

SELF-DEFENCE,

NECESSITY, AND DURESS

This chapter will outline three defences that may apply when the

accused faces exter nal threats or pressures. Unlike mistake of fact or

intoxication, these defences are not derived from the fault element of the

particular oence, and t hey can apply even though the accused commit-

ted the actus reus in a physically voluntary manner and h ad the mens

rea required for the oence. For example, a person who intentionally

kills another may nevertheless have a defence of self-defence. Those

who intentionally break into a house to save them selves from freezing

to death may have a defence of necessity and a pers on who intentionally

assists in a robber y because of death thre ats may still have a defence

of duress.

All the defences exami ned in this chapter operate as complete

defences that result in the accused’s acquittal. In each case, there must

be a reasonable doubt about each requirement of the defence. Unlike in

the cases of mental d isorder, automatism, or extreme intoxication, the

accused does not have to establish self-defence, necessity, or duress on

a balance of probabilities.

All three defences require a person to have acted reasonably in

response to exter nal pressures. In self-defence, these exter nal pressures

are violence or threats of force from the victim; in duress, threats of

serious harm f rom third parties; and in necessity, dire circum stances of

peril. The Supreme Court has obser ved that self-defence, necessity, and

duress “all ari se under circumstances where a person is subjected to an

CR IMIN AL LAW368

external danger, and commits an act that would otherwise be criminal

as a way of avoiding the harm t he danger presents.”1

The common requirement that the accused res pond to these pres-

sures in a reasonable fashion raises the familiar issue of how object-

ive standards should be applied to ensure fa irness towards ind ividual

accused. This issue f‌irst arose in the context of self-defence claims by

women who killed abusive partners. The Court’s landm ark decision

in R v Lavallee2 to consider par ticular exper iences and circumstances

that the accused faced in determining whether the accused re asonably

perceived a threat and acted reasonably has had implications for all the

defences examined in t his chapter.

The Supreme Court has accepted a modif‌ied objective standard

that invests the re asonable person with the relevant characterist ics and

experiences of the accu sed for all three defences examined in thi s chap-

ter, as well as the defence of provocation, which will be examined in

Chapter 10, because it provides a partial defence th at reduces murder to

manslaughter. This approach to endowing the reasonable person with

similar cha racteristics and ex periences as the accused st ands in con-

trast to the Court’s decision that a mod if‌ied objective standard based on

an individuated or contextual re asonable person is generally not appro-

priate in applying the objective fault standards discussed in Chapter

5.3 The modif‌ied objective standard us ed to administer thes e defences

responds to the danger of holding accused to unreasonable standards

of restraint, but it also ri sks blurring the distinction bet ween subjective

and objective standards and under mining social i nterests in requiring

people to satisfy general stand ards of reasonable conduct.

Some of the defences examined in t his chapter — self-defence,

defence of property, and duress (as applied to principal oenders) — are

codif‌ied, whereas others such a s necessity and duress (as applied to

secondary parties) are common law defences that the courts have rec-

ognized and developed.4 Overly restrictive statutory or common law

defences may violate section 7 of the Charter b y allowing t hose who

have acted in a morally involuntary ma nner to be punished. More-

over, defences should not be subject to any special deference under the

1 R v Hibbert, [1995] 2 SCR 973 [Hibbert].

2 [1990] 1 SCR 852 [Lavallee], discussed b elow in this chapter.

3 R v Creighton, [1993] 3 SCR 3 [Creigh ton], discus sed in Chapter 5, Section C(1).

4 Section 8(3) of the Criminal Code, RSC 1985, c C-46 [Code] has be en interpreted

as allowin g courts to develop and recogni ze new defences. Entrapment, which

was exam ined in Chapter 2, Section B(2)(d), has been developed as a common

law defenc e.

Self-Defence, Neces sity, and Duress 369

Charter.5 The Supreme Court has struck out the requirement in the

statutory defence of duress that the t hreat must be of immediate death

or bodily harm a nd that the threat must be from a person who is present

at the time that the accused commits the crime under dures s on the

basis that they could result in the conviction of a person who has no

other reasonable choice but to commit a crime.6

The Court has read in common law concepts to what rema ins of the

section 17 duress defence. Consistent with the common law defence of

duress and necessity, an accused who claims the section 17 defence

must now demonstrate a reasonable basis for their belief in a threat, a

close temporal connection between the th reats and the commission of

the alleged crime, the ex istence of no safe avenue of escape, and pro-

portionality between t he threats faced and the crime committed.7 This

has brought the section 17 defence that applies to principal oenders

and the common law defence that applies to parties much closer. The

section 17 defence still, however, has a categorical list of oences that

Parliament has deemed too ser ious to be excused that is not present

in the common law defence. In other words, Parliament remain s more

inclined to impose categorical re strictions on defences than court s,

which, consistent with the common law method, shape defences on a

case-by-case basis.

A. C ONCEPT UAL CONSIDER ATIONS

1) Excuses and Justif‌ications

Criminal law defences are sometimes classi f‌ied as excuses or justif‌i-

cations. A defence that excuses a crime is one that acknowledges the

wrongfulness of t he action but holds that in the circumstances the

accused should not be punished for the crime. The Supreme Court has

stated that excuses rest

on a realistic a ssessment of human we akness, recogni zing that a lib-

eral and humane cr iminal law cannot hold people to the str ict obedi-

ence of laws in emergency situ ations where normal huma n instincts,

whether of self-preser vation or altruism, over whelmingly impel d is-

obedience . . . . Praise is indeed not bestowed , but pardon is, when

one does a wrongful act u nder pressure which . . . “overstrai ns human

5 R v Ruzic, 2001 SCC 24 [Ruzic].

6 Ib id.

7 R v Ryan, [2013] 1 SCR 14 [Ryan].