Assessing credibility tends to be one of the most challenging aspects of conducting workplace investigations. This is especially the case when the investigation relates to one or more alleged incidents between two individuals for which there is no witness or documentary evidence. Unless a respondent admits all the allegations (which rarely happens), an investigator will usually need to assess credibility – this cannot be avoided.
I have put together the following 12 guiding principles to help investigators assess credibility:
- Investigators need to know how to assess credibility to make findings of fact. This is because evidence must be credible to rely upon it; relying on evidence that is not credible is a legal error. Credibility also needs to be assessed when there are competing versions of events.
- To assess credibility, investigators must determine whether the interviewee believes their evidence to be true (honesty) and whether they are accurately relaying their evidence (reliability). There are various reasons why a person’s evidence may not be reliable — e.g., passage of time, alcohol consumption, poor memory. An interviewee can provide unreliable evidence but honestly believe their evidence to be true. However, the reverse doesn’t hold true: a person who is not honest cannot provide reliable evidence.
- Investigators must look for “clues” in the evidence to assess whether a person is credible. They have to “dig” into the evidence to find these clues, rather than to rely on the interviewee’s demeanour (e.g., lack of eye contact).
- There are many clues that can suggest that an interviewee is credible, including (but not limited to) that the relevant witnesses and documents corroborate their evidence; they do not exaggerate or embellish their evidence; their evidence is detailed; there is an absence of a motive to fabricate evidence; they make concessions against their own interests; they answer questions directly and in a straightforward manner.
- Conversely, there are many clues that an interviewee may not be credible, including (but not limited to) that they provide internally inconsistent evidence; their evidence is at odds with the evidence of the relevant witness and documentary evidence; they provide exaggerative evidence; they are evasive; they speculate; they have an “axe to grind” against the other party.
- The investigator must provide reasons in the investigation report to support their credibility assessment. The reasons are the explanation of the clues that the investigator is relying upon to assess credibility.
- A strong credibility reason (e.g., a document that corroborates the evidence) can stand on its own. A weaker credibility reason (e.g., a lack of motive to fabricate) needs to be packaged with other reasons to avoid scrutiny.
- An investigator can decide that an interviewee is credible for all, some, or none of the allegations. Investigators do not need to decide that a person is entirely credible or entirely not credible.
- Most investigation reports do not need one standalone credibility assessment section. This is because credibility is often not an “all or nothing” proposition, especially in cases where there are multiple allegations. Credibility should typically be assessed in the findings for each allegation.
- While credibility should be assessed by allegation, the entirety of an interviewee’s evidence needs to be considered. This is because serious credibility issues on some allegations (e.g., evidence that changes upon each retelling) may mean that the interviewee cannot be found to be credible on other allegations.
- Credibility must be assessed even if there are many different competing versions of events (e.g., if there are many witnesses who provided different accounts); the investigator cannot abstain from doing a credibility assessment because there is conflicting evidence. It is an error to do so.
- There are situations for which corroborating evidence may not exist (e.g., one-on-one interactions). In those situations, it is an error to find that the complainant is not credible because of a lack of corroboration. The interviewee’s credibility must be assessed without considering the lack of corroboration.
I know that these principles may, on paper, seem straightforward. However, they tend to be challenging to put into practice. I have two suggestions that can help with this. First, investigators can review relevant case law to understand how decision-makers assess credibility. It can be helpful to examine how they reason through these assessments. Second, investigators should consider having a sample of their investigation reports reviewed by a senior practitioner who has a strong understanding of credibility concepts. In our practice, I am generally the person who provides that guidance to our internal investigators and clients.
Ultimately, assessing credibility is about carefully analyzing the evidence and crafting well-articulated reasons to support the conclusions reached. The more investigators practice these skills—and receive feedback on how they are applying them—the more confident their credibility assessments will become. I hope these 12 guiding principles provide a useful framework for doing just that.
