Evidence of trade custom is evidence that shows the actions of others in the same industry. Trade custom evidence is relevant only if the proponent of the evidence can demonstrate that the custom was prevalent in the relevant locality at the time of the disputed event.
While evidence of similar happenings is generally inadmissible, there are limited circumstances in which a court may admit such evidence. Examples of how courts evaluate similar happenings evidence are discussed below:
Evidence of previous similar claims is generally inadmissible to demonstrate the falsity of the present claim. However, if the proponent of the evidence relating to the prior similar claim can make a substantial showing that the similar prior claims were “false” claims, the evidence is usually relevant and admissible.
Evidence of prior similar accidents is admissible when the prior accidents were caused by the same condition or conditions as the incident in dispute, and this evidence is offered to prove
a. That the alleged condition(s) existed;
b. That the defendant had knowledge of the condition(s) that caused the current injury. Note: Evidence about the absence of prior, similar accidents or claims is generally inadmissible; however, evidence of prior contract is usually admissible so long as the contract was between the parties to the litigation, not third persons.