In basketball, a backdoor play is when a player without the ball gets behind the defense and receives a pass for an easy score. This can be executed if the defenders are unaware of the open space behind them. There is such a play available in the courtroom the defense may be unaware of as well. Federal Rule of Evidence 104 provides an attorney with backdoor means of satisfying preliminary questions of fact needed to introduce a particular items of evidence. For example, let’s say there is a document you wish to introduced into evidence that contains an expert opinion of a witness who will not be called at the time of trial to testify. Under Rule 104(a) of the Rules of Evidence you can establish the witness’s qualifications without actually calling the witness to testify at the time of trial. This portion of the Rule provides:
“(a) IN GENERAL. The court must decide any preliminary question about whether a witness is qualified, a privilege exists, or evidence is admissible. In so deciding, the court is not bound by evidence rules, except those on privilege.”
This means the court is free to suspend the Rules of Evidence in making this determination and could theoretically rely on a copy of the doctor’s curriculum vita or an affidavit of the doctors qualifications in allowing a copy of a hospital business record into evidence as this deals with whether a witness is qualified to testify.
A court could look at the substance of an alleged statement of a co-conspirator to determine if it was in furtherance of the conspiracy and would not be limited to solely independent evidence as this a preliminary question of fact the court is responsible for deciding.
A witness may be unavailable and you can only establish this through hearsay. Remember the Federal Rules of Evidence are suspend on preliminary questions of fact (i.e. foundational prerequisites)! Once you grasp this nuance in the Rules of Evidence there are a lot of preliminary issues and problems you can use this rule to solve. It can really save your bacon at trial.