In an appeal from convictions for first degree murder and five related felonies, the case is remanded for a limited evidentiary hearing on the issue whether removal and replacement of a sitting juror during the trial was justified by his exchange with the defendant of gestures that might have been Masonic signs. No connection between defendant and the Freemasons was communicated to the jury during voir dire, and the defendant has not demonstrated actual prejudice resulting from extensive voir dire questioning of prospective jurors concerning involvement with Freemasons. However, the trial court committed plain error when it removed and replaced the juror during the trial without questioning or interviewing him, or conducting a hearing into possible links to Freemasonry, as well as the meaning of - and reason for - his hand gestures or signs made in open court. There was also no proceeding to determine the juror's truthfulness during voir dire, or his ability to render an impartial verdict. While a trial court's decision to remove a juror is reviewed for abuse of discretion, when a non-frivolous suggestion of bias or a tainting incident is made the trial court must undertake an adequate inquiry to determine whether the alleged incident occurred and, if so, whether it was prejudicial. In this case, despite circumstances raising strong suspicions, without a hearing to determine whether there was actual bias, the trial court lacked a basis upon which it could remove the juror, and a basis upon which it could conclude that the defendant received a fair trial. At oral argument of this appeal, defendant agreed that remand for a post-trial hearing is a suitable remedy to address the trial court's error. Accordingly, a record remand to the Superior Court is directed, for conduct of a hearing as specified in this opinion on whether the juror was untruthful during voir dire in failing to respond to any of the trial court's questions about Freemasons, and whether the exchange of alleged Masonic gestures or signs between the juror and the defendant during the trial justified removal and replacement of the juror.