Before counsel has an opportunity to challenge prospective jurors, the trial judge performs an in-court, pre-screening process designed to address issues of competency, obvious partiality, and personal hardship (Criminal Code s. 632).
It is important for counsel to pay close attention to which prospective jurors are seeking an exemption from service and on what grounds.
One potential concern is that when seeking an exemption, a prospective juror may convey prejudicial information about the accused to the judge in the presence of the panel (for example, by conveying that the accused is a "bad guy" with a long history of similar criminal activity). The introduction of prejudicial information during the pre-screening process may call into question the impartiality of the panel.
Another potential concern is when the judge refuses prospective jurors' requests to be exempted from service. Counsel may want to consider exercising peremptory challenges should the court clerk randomly select these prospective jurors a later stage. An accused may not want to have his fate decided by someone who has asked to be exempted from service at the beginning of the proceeding.