["Applied Cognitive Psychology, Volume 40, Issue 4, July/August 2026. ", "\nABSTRACT\nWorkplace investigations aim to prevent future harm by uncovering event causes. While expertise guides decisions effectively, it cannot remove bias. This research tested a fact‐checking intervention to reduce bias in investigations. Professional investigators and students received biasing background information and then a witness statement with potential facts and opinion‐based comments. Participants separated the opinions from potential facts either before or after judging the statement's diagnostic value, witness's credibility, and likely causes for the event. Fact‐checking before reduced participants' misclassifications of opinions as potential facts, yet the timing of fact‐checking did not affect participants' credibility assessments or causal judgments. Professionals misclassified fewer opinions as facts, and professionals who fact‐checked early rated the witness statement as less diagnostic. This research showed that fact‐checking improved objective evaluation of witness evidence but did not enhance higher‐level judgments. This highlights the complexity of bias mitigation and the value of context management strategies in promoting impartial investigations.\n"]