(a) In any criminal prosecution to be tried to the jury in the Superior Court if it appears to the court that the trial is likely to be protracted, the court may, in its discretion, direct that, after a jury has been selected, two or more additional jurors shall be added to the jury panel, to be known as “alternate jurors”. Such alternate jurors shall have the same qualifications and be selected and subject to examination and challenge in the same manner and to the same extent as the jurors constituting the regular panel, provided, in any case when the court directs the selection of alternate jurors, the number of peremptory challenges allowed shall be as follows: In any criminal prosecution the state and the accused may each peremptorily challenge thirty jurors if the offense for which the accused is arraigned is punishable by death or life imprisonment without the possibility of release, eighteen jurors if the offense is punishable by life imprisonment, eight jurors if the offense is punishable by imprisonment for more than one year and for less than life, and four jurors in any other case.

(b) Alternate jurors shall be sworn separately from those constituting the regular panel, and the oaths to be administered shall be as provided in § 1-25.

(c) Alternate jurors shall attend at all times upon trial of the cause. They shall be seated when the case is on trial with or near the jurors constituting the regular panel, with equal opportunity to see and hear all matters adduced in the trial of the case. If, at any time, any juror shall, for any reason, become unable to further perform the duty of a juror, the court may excuse such juror and, if any juror is so excused or dies, the court may order that an alternate juror who is designated by lot to be drawn by the clerk shall become a part of the regular panel and the trial or deliberation shall then proceed with appropriate instructions from the court as though such juror had been a member of the regular panel from the time when the trial or deliberation began. If the alternate juror becomes a member of the regular panel after deliberations began, the jury shall be instructed by the court that deliberations by the jury shall begin anew. A juror who has been selected to serve as an alternate shall not be segregated from the regular panel except when the case is given to the regular panel for deliberation at which time such alternate juror may be dismissed from further service on said case or may remain in service under the direction of the court.