In Coots v. State, 826 S.W.2d 955 (Tex. App.--Houston 1st Dist. 1992, no pet.), the court of appeals reversed because the trial court's bailiff--who was not designated as a witness before trial--testified about the ease with which an electronic monitoring bracelet could be removed with pliers. Id. at 960. His testimony undermined the defendant's alibi that he could not have committed the crime because his monitoring bracelet did not show he left his house. Id. The State contended that it could not have known that it would use the bailiff's testimony before it heard the defense witnesses. Id. The court of appeals held that the State should have known the defendant's strategy from his opening statement and should have notified the trial court that it would probably call the bailiff to testify. Id. at 960-61. The court held that the admission of the bailiff's testimony was error and that the error was "obviously harmful because the bailiff heard and contradicted vital testimony of two critical defense witnesses concerning the monitor." Id. (citing former Tex. R. App. P. 81(b)(2)). The current substantial-rights standard is more challenging for appellants to meet. Further, the facts on which the bailiff in Coots testified were apparent from the opening statement and critical to whether the defendant could have committed the crime. Coots, 826 S.W.2d at 960-61. The Court of appeals held that the trial court abused its discretion by allowing a bailiff to testify as a rebuttal witness for the prosecution. Id. at 960-61. The prosecution argued that the trial court did not have to exclude the bailiff from the courtroom because it did not plan on calling the bailiff as a witness until after the defense presented evidence that a electronic monitoring bracelet could only be removed by cutting it. Id. at 960. However, the court of appeals determined that the bailiff should have been excluded because the prosecutor was aware that the defense was going to rely on the electronic monitoring bracelet to prove his alibi. Id. at 960-61.