When someone is going to tell you a lie, and they know they are going to lie to you going into it, they will set the stage with overly convincing and descriptive prologues. A specific, fact filled prologue should include relevant details as to how the situation came about, but usually will not include inconsequential details.
Ex: “It was a normal day and I had just finished my shift. My car was parked in the darkest area of the parking lot but I didn’t think much of it. It was evening now and dark outside. My car was parked far away from the restaurant that I work at. I know there have been reports of muggings but I don’t normally worry about that stuff happening to me. We had a good day at work, so I made some good money off of tips. As I was walking to my car, I noticed a man following me but I didn’t want to be paranoid so I ignored it. I continued to my car and as I was getting close to it I felt a sudden yank on my purse…”
In this example we can see the subject is setting the stage for the incident, likely to be a robbery. This would be a strong indicator the subject does not intend to be entirely honest and is expending considerable effort to make the story (exactly what it is) believable. Here is a look at a more honest introduction.
“I had just finished my shift at the restaurant and was walking to my car when a strange man started following me. He was white with a brown coat on and was wearing a beanie style cap. He was slender and had a scruffy appearance. I started to pick up the pace so I could get to my car quicker. I was a little nervous because I had made some decent tips that day and I was carrying more cash on me that normal. Suddenly I felt a yank on my purse…”.
In the second example, we can see the speaker/writer has stuck to facts relevant to the incident. Because the subject is telling the truth, there is no concern that they will not be believed. The truth is on their side and they expect to be believed. In the deceptive example, however, the subject knows the story is not true and therefore relies heavily upon convincing language in order to make it more believable.
Also, an introduction that contains setting of the stage will usually be excessively wordy. Comparing the two examples, the first has 131 words, the second has 92. I have found that prologues that contain more than 30% of the entire word count of the story (in written or transcribed statements) tend to have stage setting. This high of a percentage is a strong indicator of deception (A. Sapir, isiscan.com).