Principles of Courtroom Testimony

In the courtroom, there are two different types of witnesses: those who testify to facts and those who can also offer opinions. The former is referred to as a fact witness who testifies to what that person saw, heard or experienced. The latter is referred to as an expert witness who can also state their observations but is also permitted to give opinion testimony in the courtroom. However, the opinions an expert is permitted to express in court are limited to the expert’s area of expertise, which is determined prior to offering opinions. Forensic pathologists play a pivotal role in the legal system typically as expert witnesses in criminal cases, rather than civil cases. There are legal distinctions between criminal and civil cases, which are reflected in their respective processes, standard of proof and legal remedies. The main issue in criminal cases is that the accused’s liberty, and in some jurisdictions—life, is at stake. In civil cases, finances or property is in jeopardy. Testimony makes up a small but significant portion of the medicolegal practice of a forensic pathologist. Although there is a wide variety of legal systems, this chapter will focus primarily on the criminal system of Ontario, Canada, which its colonial origins are reflected as an Anglo-Saxon legal system. It is recommended that each individual consider how their work functions in the legal system in which they live and work.