Ignorance is bliss when conducting witness interviews
Current investigative interviewing guidelines recommend interviewers review all available case information prior to questioning a witness. However, a recent study suggests prior case knowledge may actually be detrimental to the outcome of an investigative interview.
A team of researchers, including Florida International University legal psychologist Nadja Schreiber Compo, are the first to study blind interviewing through observation, a technique contrary to what is recommended by the National Institute of Justice. The findings were recently published in the journal Memory, revealing blind interviewers—those with little to no knowledge about the crime—elicited more detailed and accurate information than those who had correct information about the crime prior to the interview.
"This line of research is directly relevant for real-world witness and victim interviewers who thus far have oftentimes been told to review a case file before conducting a witness interview," Schreiber Compo said. "Our findings suggest that an interviewer with no background information may at the very least not be at a disadvantage, possibly at an advantage, when interviewing a witness."
Nearly 350 people participated in the study and were randomly assigned the role of either the witness of a crime, interviewer or blind interviewer. The "witnesses" viewed one of two videos that depicts a crime, each with varied details. The "interviewers" were given summaries of the crime, sometimes with correct information and sometimes incorrect. "Blind interviewers" were given no information prior to conducting their interviews. All interviewers were asked to write reports at the conclusion of the simulations.
Results showed correctly informed interviewers stopped short of collecting all possible details because they were influenced by the information contained in the pre-interview report. Blind interviewers were more likely to begin the interview with a non-suggestive question and recalled more details than the informed interviewers in their reports. Witnesses questioned by blind interviewers reported more information and more accurate details than those interviewed by informed interviewers.
Researchers concluded blind interviewing may be an appropriate and viable strategy for conducting investigative interviews if it leads witnesses to be more forthcoming and interviewers to work harder at gathering detailed accounts to aid the investigation. The study was conducted in collaboration with researchers from Barry University and funded in part by the American Psychology-Law Society Grants-In-Aid Award.
Schreiber Compo's research focuses on investigative interviewing and eyewitness memory, especially in the context of vulnerable witnesses such as children or the intoxicated. She is interested in potentially detrimental and beneficial interviewing techniques and their underlying cognitive and social mechanisms to improve the quality and quantity of witness and victim recall. She has trained the MDPD homicide, special victims unit and robbery investigators on best practices for witness interviewing and identification procedures.