A successful criminal defense lawyer must know the Rules of Evidence in New York. As a general rule, the trial judge is the gatekeeper when it comes to what evidence a jury is able to consider. However, judges are bound by certain rules of evidence which are written by lawmakers. The Guide to New York Evidence closely mirrors the Federal Rules of Evidence, but there are a few differences.
The most basic rule of evidence is that only relevant evidence is admissible. Relevant evidence is defined a, “evidence having any tendency to make the existence of any fact that is of consequence to the determination of the proceeding more probable or less probable than it would be without the evidence.” However, not all relevant evidence is admissible in a New York criminal trial.
Under rule 4.01(2) all relevant evidence is admissible unless it is precluded by the state or federal constitution, by statute, or by the common law. In New York, there are several rules that can help defendants, as well as few that can hurt them. For example, under Rule 4.27, evidence that a defendant has previously been convicted of a crime is only admissible when it is an element of an offense or, “otherwise essential to the establishment of a legally sufficient case.” If the prosecution cannot establish one of these two situations exist, then a defendant’s prior convictions are inadmissible.