When conducting investigative interviews and criminal interrogations, at what point do you disclose the evidence you have in your investigation to the individual you are talking with? Many investigators take the position that if they have a strong case, at least as far as the evidence goes, it is best to go in with both barrels and lay it all down, thinking that the weight of the evidence against them will cause them to quickly see the light, fall on the sword and confess. Sometimes that may work, especially for less sophisticated criminals, and there is scientific support showing that the weight of evidence against a suspect is a major factor prompting confessions. But . However, . But . . bu bfor those sneaky, quick thinking, been-around-the-block types, laying the evidence out up front can provide them with the material they need to weave their web of deceit. They can use the evidence that you disclose and provide information to account for why it is there, possibly negating or significantly reducing the impact of the evidence. It is often best, regardless of the strength of your evidence, to obtain information from the individual first, either through an oral narrative account or a written statement. By simply asking them an open question about an incident such as "Tell me everything that happened", or asking them an open question about particular time frame such as "Tell me everything that happened from the time you got home from school yesterday until you went to bed last night", whereby covering the time frame of the incident under investigation, you will gather information to compare against the evidence you have. This will give you a better assessment of the individual’s veracity and will serve to make the disclosure of the evidence even stronger and more impactful.
If their statement or account of their activity contradicts the evidence, you can point that out...one by one...thereby building the psychological stress and pressure, as well as their cognitive load, because now they have committed themselves to a story but it flies in the face of the evidence. When they are lying, they know the truth of what "really" happened, but they have a script they provided you that is falling apart. Now they are obviously caught and they cannot talk their way out by weaving their tale of woe into the evidence, because they already committed to it. When the psychological stress and cognitive load increases, we will often see verbal and behavioral changes that will help focus our questions to prompt more detail from them until it is obvious to them that the gig is up.
This is a narrative based interview/interrogation and is non confrontational. The key is to gather as much evidence and background information before the interview as possible so you have the ability to compare it against their story. Obtain a written or oral account from them up front through an open question; ask probing questions relative to their response, then see if there are contradictions in their story that conflict with the known evidence. If so, point that out one by one...building the pressure and cognitive load and building your case, while systematically dismantling their story.