If given the time, we could probably come up with a number of reasons a suspect won't confess, a hostile witness won't cooperate or why the victim won't disclose. If we then reviewed our "list" objectively we might find that we have placed a large portion of the blame on our subject and were partially if not fully blind to any problems we may have created. It's time to give ourselves and our subject a break. The impasse may in fact have been created because of there being too many choices to be made by us and our subject.
All too often when entering an interview room, we like to go in "armed to the teeth" with information and facts. Being fully loaded with evidence is certainly not a bad thing but how we choose to present that information can be a handicap for the interviewer as well as the subject. With so many choices to make about what topics to address, how to address them, what order and more, we get caught up in the "planning" and can bungle the "presentation." Because we have too many choices to make we may see a successful interview as a long and difficult campaign with no assurance of success and even a higher probability of early failure. To overcome this problem, try dealing with and presenting only one issue at a time and strive to win small battles and not the whole "war" with one big "atomic" question that tries to incorporate multiple issues. You'll find you'll be able to focus more on your subject, miss fewer of the important responses and increase your chances of overall success.
Far too many choices presented to the victim, witness or suspect also has a higher probability of negative outcome. Contrary to common belief, it is known in the sales profession too many choices presented to the customer kills more sales than they make and the same behavior response applies to the interview room. Asking for agreement or concession from your subject on several issues at once makes the ultimate decision by the subject much more difficult. When we increase the difficulty of the decision making cycle for our subject, the longer it will take for the person to make their decision to comply, cooperate or confess. The longer the decision-making cycle is extended for our subject, the greater the chance that the results of the decision process will be negative and thus harder for us to reverse and overcome.
Review your case before you conduct your interview. Break down the case interview objectives into smaller more manageable tasks and move toward your goals of cooperation, compliance and admission by winning small victories by reducing the choices to be made at any one time. You'll improve your chances of a successful interview.