N.Y. CPL Law § 270.30

§ 270.30 Trial jury; alternate jurors.\n 1. Immediately after the last trial juror is sworn, the court may in\nits discretion direct the selection of one or more, but not more than\nsix additional jurors to be known as "alternate jurors", except that, in\na prosecution under section 125.27 of the penal law, the court may, in\nits discretion, direct the selection of as many alternate jurors as the\ncourt determines to be appropriate. Alternate jurors must be drawn in\nthe same manner, must have the same qualifications, must be subject to\nthe same examination and challenges for cause and must take the same\noath as the regular jurors. After the jury has retired to deliberate,\nthe court must either (1) with the consent of the defendant and the\npeople, discharge the alternate jurors or (2) direct the alternate\njurors not to discuss the case and must further direct that they be kept\nseparate and apart from the regular jurors.\n 2. In any prosecution in which the people seek a sentence of death,\nthe court shall not discharge the alternate jurors when the jury retires\nto deliberate upon its verdict and the alternate jurors, in the\ndiscretion of the court, may be continuously kept together under the\nsupervision of an appropriate public servant or servants until such time\nas the jury returns its verdict. If the jury returns a verdict of guilty\nto a charge for which the death penalty may be imposed, the alternate\njurors shall not be discharged and shall remain available for service\nduring any separate sentencing proceeding which may be conducted\npursuant to section 400.27.\n