Foreign Law Evidence: Distinct Approaches in the U.S. and Canada

In both the United States and Canada, expert testimony plays a crucial role in aiding the court to accurately assess the law of another country and resolve foreign law issues, such as whether a foreign country’s legal system adequately protects the best interest of a child. However, the two countries adopt distinct approaches to evaluating expert testimony on foreign law.

In the U.S., it remains the prevailing rule that expert witnesses of foreign law are not required to meet any special qualifications, and their testimonies are not required to meet specific evidentiary criteria. To be qualified as a foreign law expert, a witness simply needs to demonstrate sufficient personal knowledge of a foreign country’s law to the satisfaction of the U.S. court. An expert witness on a foreign country’s law does not need to be a lawyer of that country, or a legal scholar specializing in that country’s law. In fact, a foreign law expert witness does not need to be a lawyer or a legal scholar at all. In some family law cases, lay witnesses, who had been parties to custody disputes in foreign countries, have been permitted to testify as experts on foreign law. Furthermore, U.S. courts may consider any relevant material or source on foreign law, including written and oral testimony that would not be admissible under standard evidentiary rules.

Although in U.S. courts the purpose of expert testimony on foreign law is to aid the court in determining the content of the applicable foreign law - not to apply it to the facts of the case - expert witnesses often become hired guns. Judge Richard Posner sharply criticized “the banes of” foreign law experts, noting that foreign law experts are typically chosen for either their agreement with the paying client’s views or their willingness to endorse the views urged by the client. He pointed out that such foreign law experts do not provide “neutral illumination of issues of foreign law.” The widespread presence of problematic foreign law testimonies in U.S. courts can largely be attributed to the inadequate scrutiny given to either foreign law expert witnesses’ qualifications or the admissibility and probative value of their testimony.

In contrast, Canadian courts require that expert testimony on foreign law meet the rigors of a two- stage process. An expert’s testimony on foreign law must first meet each of the five factors enumerated in the threshold test, namely:

1. that it is logically relevant;
2. that it is necessary to assist the trier of fact as it is outside the knowledge of the trier of fact;
3. that it is not subject to any exclusionary rule;
4. that the person can be properly qualified and able to fulfill their duty as an expert; and
5. that the person is impartial, independent, and unbiased.

Secondly, even if the threshold test is met, the court must fulfill a gatekeeping function and may exclude proposed expert evidence when its probative value is outweighed by its prejudicial effect.

A recent Ontario wrongful retention case demonstrates how Canadian courts apply the two-stage test in international family law cases. When qualifying the witnesses, the Ontario court focused on their ability to provide fair, objective, and non-partisan assistance to the court. The court deemed it critical that a witness can use primary sources of foreign law and draw on their personal experience to form a neutral opinion. In assessing the admissibility of testimony on foreign law, the Ontario court focused on both the relevance and objectivity of the proposed testimony.

Applying the rigorous criteria of the two-stage test, the Ontario court admitted expert testimonies that were directly relevant to the central issues in the case, supported by primary sources, and grounded in the witnesses’ firsthand experience in the relevant foreign country.

The articles on Chinese family law in this issue illustrate the increasingly complex and ever evolving legal landscape in China. Given the complexity of family law around the world, it is unlikely that a witness, who has no legal training and practical experience in a foreign country’s law, can provide the court with objective, independent analyses of foreign law. Thus, it is critical for U.S. courts and attorneys to adopt a more rigorous approach to scrutinizing foreign law evidence. Canada’s two-stage test offers a valuable model for selecting qualified foreign law experts and evaluating their testimonies.