The credibility of a witness depends on such factors as whether he or she:
- Has direct knowledge of the facts in issue, as opposed to second-hand or “hearsay” information;
- Has a motive to fabricate information, or the contrary:
- Has provided reliable information in the past, or the contrary;
- Is willing to be identified, at least to investigators (unless the witness honestly believes himself or herself to be in significant danger if identified).
Unless there are obvious reasons to doubt the witness’s credibility, however, the investigator should not be too concerned about trying to evaluate it at this stage. Many useful reports are provided by anonymous informants or persons with personal interests in the investigation, such as losing bidders or discharged employees.
If the report appears to be plausible, the investigator should independently test the allegations by, for example, looking for other red flags of the alleged misconduct, and decide whether to proceed based on the results of all of the information obtained.