Obtaining the Statement
Experienced investigators know that the most difficult way to obtain useful information is the simple question-and-answer method, which usually results in the subject answering "yes" or "no". The point in eliciting a statement is to ask open-ended questions. This is done to avoid prompting the subject and encourage a “naturalness” with the subject providing new information in response to your questions.
Investigators should ask very few detailed questions to avoid introducing their own information (case facts/findings) into the subject's statements. By giving the subject little information and coaching, the investigator seeks to obtain an uncontaminated version of the events. Most subjects will talk with relatively little encouragement or prompting. Even if the subject shows signs of reluctance, it's often possible to persuade them into making a statement. Eliciting a statement is not a 50/50 proposal. A successful interview would have the subject speaking about 95% of the time, and the investigator only about 5%. This minimizes the investigator's contribution to the final statement.