An offer of proof is a lawyer's explanation to a trial judge regarding the admissibility of evidence or testimony that might not otherwise be allowed. This often happens when the opposing counsel objects to the testimony of a witness, or to a particular line of questioning. The objection is usually based on a claim of irrelevance. It can also occur in response to an adjudicator who rules against allowing a piece of evidence to be presented in front of a jury. An offer of proof is the lawyer's opportunity to convince the judge that the evidence is relevant and should be presented in court.
When a lawyer makes an offer of proof, he or she is usually permitted to speak to the judge about the type of evidence he wishes to present to the jury. He explains its relevancy. An informal offer of proof is a lawyer’s summary of what he intends to ask, and what he expects the witness will say on the stand. IN other words, he explains how it will prove his case.
After hearing the attorney's account, the judge may allow him or her to proceed with the witness in front of the jury. Sometimes, however, the judge does not accept the lawyer's informal offer of proof. The attorney can then motion for a formal offer of proof.
A judge will usually grant this request, which preserves the right to due process. A formal offer of proof means that the lawyer is permitted to proceed with the witness in the courtroom, but not yet in the presence of the jury, meaning the attorney asks the witness questions he would have asked in front of the jury. This is the lawyer's opportunity to prove to the judge that his line of questioning does, in fact, lead to evidence that is important to his case. The judge can then determine whether or not to allow the lawyer to ask the same questions in front of the jury.
All testimony and other evidence presented during an offer of proof are recorded by the court reporter. If the adjudicator decides not to allow testimony in front of the jury, the lawyer has the option of filing an appeal if he or she loses the case. An appellant judge could then decide if the trial court judge's decision to exclude the evidence was appropriate. If the appellant judge finds that the excluded evidence was crucial in the outcome of the jury trial, the verdict could be overturned.