Which principle best guides investigators to avoid bias during interviewing?

• A. Presumption of innocence and objectivity; rely on evidence rather than assumptions.
• B. Always assume the suspect is guilty.
• C. Let personal beliefs guide questioning.
• D. Ignore evidence if it disrupts the flow.

Answer: (B)

The main idea is to prevent bias by upholding presumption of innocence and staying objective, grounding conclusions in evidence rather than assumptions. In practice, this means treating people as innocent until proven otherwise and using neutral, open-ended questions that let them describe events without steering them toward a particular conclusion. Focusing on evidence helps you test hypotheses fairly and reduces confirmation bias, so you don’t chase information that only fits a preconception. If you start from the assumption that someone is guilty, you’re more likely to ask leading questions, interpret statements to fit that belief, and miss important exculpatory details. Similarly, letting personal beliefs drive questioning or ignoring evidence to keep the interview flowing undermines accuracy and can distort what actually happened. Keep the inquiry evidence-based, neutral, and adaptable as new information emerges.