Challenge for Cause
Section 638 provides both Crown and defence counsel to make a challenge for cause on the basis of several available grounds:
Challenge for cause
638. (1) A prosecutor or an accused is entitled to any number of challenges on the ground that
- (a) the name of a juror does not appear on the panel, but no misnomer or misdescription is a ground of challenge where it appears to the court that the description given on the panel sufficiently designates the person referred to;
- (b) a juror is not indifferent between the Queen and the accused;
- (c) a juror has been convicted of an offence for which he was sentenced to death or to a term of imprisonment exceeding twelve months;
- (d) a juror is an alien;
- (e) a juror, even with the aid of technical, personal, interpretative or other support services provided to the juror under section 627, is physically unable to perform properly the duties of a juror; or
- (f) a juror does not speak the official language of Canada that is the language of the accused or the official language of Canada in which the accused can best give testimony or both official languages of Canada, where the accused is required by reason of an order under section 530 to be tried before a judge and jury who speak the official language of Canada that is the language of the accused or the official language of Canada in which the accused can best give testimony or who speak both official languages of Canada, as the case may be.
R.S., 1985, c. C-46, s. 638; R.S., 1985, c. 27 (1st Supp.), s. 132, c. 31 (4th Supp.), s. 96; 1997, c. 18, s. 74; 1998, c. 9, s. 6.
There must be an "evidentiary foundation" for any claim of challenge for cause.
There is not a fixed rule that a jury panel should be excluded during challenge for cause.
- R v Rowe, 2006 CanLII 14235 (ON CA)
R v Hubbert (1975), 11 OR (2d) 464 at p.291
R v Sherratt, 1991 CanLII 86 (SCC),  1 SCR 509 at 527
R v Williams 1998 CanLII 782 (SCC),  1 SCR 1128, paras 1 at 13 and 55
- R v Moore-McFarlane 2001 CanLII 6363 (ON CA), (2001), 56 O.R. (3d) 737 (C.A.) at para 85
- R v Moore-McFarlane at para 85
Challenge for Bias
Under section 638(1)(b), a party may challenge a juror "for cause", alleging that the juror may not be indifferent. The test is whether there is "a 'realistic potential' that the jury pool may contain people who are not impartial in the sense that even upon proper instructions by the trial judge they may not be able to set aside their prejudice and decide fairly between the Crown and the accused …"
The purpose of challenge for cause is to screen out potential biases in juries.
The fundamental issue on challenges for cause is whether the accused can receive a fair trial pursuant to s. 11(d) of the Charter.
The party challenging cause must establish that:
- a widespread bias exists in the community; and
- some jurors may be incapable of setting aside this bias, despite trial safeguards, to render an impartial decision.
There are the "attitudinal" and "behavioural" components to partiality.
There is a presumption that jurors are capable of setting aside their views and biases in favour of impartiality between Crown and the accused and compliance with the trial judge's instructions. 
The decision to permit a challenge for cause is discretionary, but when in doubt the judge should "err on the side of permitting challenges".
Challenges will normally be directed at all potential jurors, but may be targeted at specific jurors.
The basis of challenge can be established by way of expert testimony regarding the bias alleged.
- section 638(1)(b) states "A prosecutor or an accused is entitled to any number of challenges on the ground that ...(b) a juror is not indifferent between the Queen and the accused")
- R v Find, 2001 SCC 32 (CanLII) at para 31
- R v Sherratt, 1991 CanLII 86 (SCC),  1 SCR 509 at p. 533
- R v Bennight, 2012 BCCA 190 (CanLII) at 42
- R v Find at para 32
- Find at para 32
- R v Find, 2001 SCC 32 (CanLII),  1 SCR 863 at para 26
Find at para 45
- R v Daigle, 2007 QCCA 1344 (CanLII)
- e.g. see R v Douse, 2009 CanLII 34990 (ON SC)
Background Checks of Potential Jurors
The Crown has a limited ability to make police background checks into each prospective juror for the purpose of challenges under s. 638(1)(c). Where it is done so, the results must be disclosed to the defence.
- R v Yumnu, 2012 SCC 73 (CanLII)
The questions should be “relevant, succinct and fair” and avoid invading "the privacy of prospective jurors in an attempt to probe personal feelings, opinions, and beliefs". The questions must remain "within the bounds of a legitimate inquiry into the impartiality of potential jurors".
The ability to challenge opinions is limited. Often the questions are narrow enough only to be answered yes or no.
It is solely the judge who determines the form of the question given the circumstances of the case.
R v Hubbert (1975), 11 OR (2d) 464, 29 CCC (2d) 279 at pp. 289-90 (CA), affirmed and adopted 1977 CanLII 15 (SCC),  2 SCR 267
R v Dhillon, 2001 BCCA 555 (CanLII) at para 53
R v Williams 1998 CanLII 782 (SCC),  1 SCR 1128 at para 53
R v Bulatci, 2012 NWTCA 6
R v Gayle, 2001 CanLII 4447 (ON CA), at para 22
e.g. R v Sandham (2009), 248 CCC (3d) 46 at para 3 (Ont.)
R v M.M.,  O.J. No. 5962 at para 24 affirmed on other grounds 2007 ONCA 329 (CanLII), 220 CCC (3d) 74
It is not appropriate to group jurors on the basis of race as it violates the requirement of random selection under s. 631.
There are two methods of selecting jurors on a challenge for cause. First, there is the "dynamic triers" method and then there is the "dynamic triers" method of selection.
An accused does not have a right to have a jury including members of a particular race, ethnicity or background.
An intention to challenge for cause may require written notice:
Challenge in writing
639. (1) Where a challenge is made on a ground mentioned in section 638, the court may, in its discretion, require the party that challenges to put the challenge in writing.
(2) A challenge may be in Form 41.
(3) A challenge may be denied by the other party to the proceedings on the ground that it is not true.
R.S., c. C-34, s. 568.
An intention to a challenge of the array may also require notice:
Challenging the jury panel
629. (1) The accused or the prosecutor may challenge the jury panel only on the ground of partiality, fraud or wilful misconduct on the part of the sheriff or other officer by whom the panel was returned.
(2) A challenge under subsection (1) shall be in writing and shall state that the person who returned the panel was partial or fraudulent or that he wilfully misconducted himself, as the case may be.
(3) A challenge under this section may be in Form 40.
R.S., 1985, c. C-46, s. 629; R.S., 1985, c. 27 (1st Supp.), s. 130.
(2) If the ground of a challenge is one that is not mentioned in subsection (1) and no order has been made under subsection (2.1), the two jurors who were last sworn — or, if no jurors have been sworn, two persons present who are appointed by the court for the purpose — shall be sworn to determine whether the ground of challenge is true. ...
R.S., 1985, c. C-46, s. 640; 2008, c. 18, s. 26; 2011, c. 16, s. 9.
The dynamic method of selecting jurors is intended to ensure "that the responsibility for determining the challenge for cause is shared by all jurors but the last juror selected".
The changing of triers with each selection is mandatory.
R v W.V., 2007 ONCA 546 (CanLII) at para 26
- R v W.V.
The process involving static triers was added to the Code in 2008.
Section 640(2.1) and (2.2) were added:
(2.1) If the challenge is for cause and if the ground of the challenge is one that is not mentioned in subsection (1), on the application of the accused, the court may order the exclusion of all jurors – sworn and unsworn – from the court room until it is determined whether the ground of challenge is true, if the court is of the opinion that such an order is necessary to preserve the impartiality of the jurors.
(2.2) If an order is made under subsection (2.1), two unsworn jurors, who are then exempt from the order, or two persons present who are appointed by the court for that purpose, shall be sworn to determine whether the ground of challenge is true. Those persons so appointed shall exercise their duties until twelve jurors and any alternate jurors are sworn.
R.S., 1985, c. C-46, s. 640; 2008, c. 18, s. 26; 2011, c. 16, s. 9.
The accused may apply under s. 640(2.1) to have two triers select all members of the jury. They themselves cannot become members of the jury.
Sections 640(2),(2.1) and (2.2) do not remove the judge's inherent jurisdiction to exclude jurors from the courtroom during the challenge for cause.
The instructions to the trier should contain the following elements:
- the triers are to decide if the potential juror is impartial,
- the decision is on the balance of probabilities;
- the decision must be by both triers,
- they may retire to the jury room or discuss it where they are; and
- if the triers cannot agree within a reasonable time they are to say so.
The judge must also give the triers an "adequate understanding of the nature of their task and the procedure they were to follow".
Instructions will be adequate where when "viewed in their entirety, the instructions provided [the triers] with an adequate understanding of the nature of their task and the procedure they were to follow in order to select an impartial jury”.
When dealing with dynamic triers it is necessary to repeat the instructions to each and every one of them.
Decisions of Triers
There is no right for counsel to make submissions to the triers, but may do so at the discretion of the judge.
The decision of a trier can be based not only on the answers to the questions but also on the demeanour and reactions of the potential juror.
Generally, a judge should interfere with the trier's process by making their decision for them on any prospective juror.
However, s. 640(4) permits the judge to dismiss triers who cannot agree and then empanel replacements. Such disagreement also permits the judge to dismiss the juror.
Where a trier expresses uncertainty on the choice of a prospective juror, the judge may in some cases, be able to dismiss the prospective juror.
The triers do not need to make a decision on a particular prospective juror who the defence counsel has already decided is acceptable. However, once questioning starts, the opposing side cannot simply "admit" the challenge, thus rejecting the prospective juror, as in effect the opposing side would have in effect unlimited pre-emptory challenges.
Subjects of Challenge
Challenge for racial bias requires that the applicant "establish that there is widespread bias in the community and that some prospective jurors may not be capable of setting aside their bias." The recognized prejudice against visible minorities is widespread enough that a challenge for cause will be established in most cases.
Given the difficulty of presenting evidence of racial prejudice within a community, a judge may infer it based on evidence of national or provincial wide prejudice.
Variations of race-based challenges have not always been accepted.
- R v Kematch, 2008 MBQB 260 (CanLII) at para 8
- R v Parks, 1993 CanLII 3383 (ON CA) - suggests it is established in "virtually every case"
- Kematch at para 8
e.g. see R v Spence,  3 SCR 458, 2005 SCC 71 (CanLII), - bias towards complainant who was white in an inter-racial relationship
R v Hummel, 2002 YKCA 6 (CanLII), - rejected challenge on bias that a white woman would be less likely to consent to sex with an aboriginal accused
Where an offence is gang-related and that relation creates a "reasonable risk of bias", jurors may be challenged.  Where it is adjunct to racial bias it will more likely be relevant to jury selection.
- R v B.D.S., 2014 MBQB 42 (CanLII), at para 5
- B.D.S. at para 5
Challenge on the basis of national origin has been largely rejected.
There have been a few requests for challenge on the basis of bias towards those suffering from mental illness such as schizophrenia or psychosis.