Investigative interviewing: Exploring the contamination timeline of witness memory

Gathering information that is comprehensive and accurate from witnesses is crucial to investigative decision-making. However, eliciting information from witnesses is a difficult task. Thus, the current chapter will provide an overview of the potential contamination points throughout the investigative interviewing process. More specifically, it will explore police officers’ questioning techniques during an interview and how poor questioning itself can contaminate a witness’s memory. This chapter will begin by addressing the first potential contamination point in the investigative process (i.e., police call handling). Call handlers question the witness to ascertain (1) the nature of the call and (2) what action should be taken. Next, this chapter will explore police officer’s frontline communication and their use of elicitation techniques as the second possible contamination point. Indeed, frontline police officers tend to be the first face-to-face contact that a witness experiences. Following this, the third contamination point can occur when a witness is formally interviewed. Finally, this chapter will summarize the contamination points across the interview and information gathering process. Recommendations to reduce memory contamination and how best practices can be attained will be discussed.