Legal evidence is material that can be used in pursuit of a legal case. The evidence is brought to court for the purpose of demonstrating or refuting a point related to a case. There are many different types of evidence, and legal systems in most nations have strict rules regarding admissibility of evidence, evidence collection, and related matters. The goal of carefully regulating evidence is to ensure that only evidence that is valid and relevant is brought to court.
A classic example of legal evidence is testimonial evidence from witnesses, which can include direct evidence about an event someone saw firsthand, as well as indirect evidence, like a professional opinion. Witnesses can make unreliable evidence because they can have imperfect memories or may have been influenced by things that occurred between the event and the trial. Attorneys are careful about how they question and interact with witnesses to ensure that the evidence provided will be of the highest quality possible.
Another type of evidence is documentary evidence, including paper documentation of anything relating to the trial. This can include documents such as contracts, telephone bills, and personal letters, as well as other written materials. Recordings in other mediums such as photography, audio, and video are also forms of documentary evidence. This evidence can again be direct, as in the case of a contract brought in to demonstrate the facts associated with a contract dispute, or indirect, such as a letter that may demonstrate the character of the defendant.
Demonstrative evidence is legal evidence that is designed to demonstrate or illuminate some aspect of a case. It includes things like models, charts, and other displays that help the jury understand the facts of the case. When cases are complex, seeing the details of the case walked through in a model can be useful for some jurors. For example, a computer animation could provide an overview of events at a crime scene as described by witnesses.
Real evidence is physical material from a crime. This type of legal evidence includes hairs and fibers, weapons, and other physical objects. Real evidence may be subjected to analysis in a lab as part of an investigation.
Rules of legal evidence state that the evidence must be relevant to the case and it must be presented in its original form unless there is a compelling reason not to do so. Copies of evidence are not admitted due to concerns about tampering. An exception might be a case where evidence is too fragile or has been destroyed during testing, in which case a copied version may be accepted, as long as it is clearly labeled as such.
