Often the court will hold hearings before trial to decide whether the parties can introduce the pieces of evidence at issue. These hearings are held outside the presence of the jury, generally before the jury selection process even begins. Holding these hearings before trial helps the trial move more efficiently since the parties can prepare their evidence knowing which will be allowed and there will be less interruption of the trial to deal with evidentiary issues. This process also ensures that the jury will not hear or see evidence that should not be used. When the jury sees or hears evidence that a judge later rules is not admissible, the judge will order that the jury “strike” that evidence and not consider it in their deliberations. But jurors are human and it is difficult to un-see or un-hear.

In the example from the previous page, assume that after reviewing the parties’ arguments regarding the admissibility of the defendant’s statement to police the judge ordered a pre-trial hearing. At that hearing, witnesses with knowledge of the circumstances of the defendant’s arrest and his statement would be called to testify to those observations. For example, the police officer who interrogated the defendant would likely testify to the circumstances surrounding the defendant’s statement. The judge will hear the sworn testimony and decide whether the evidence can be used at trial or not.