Pre-incident indicators are those detectable factors that occur before the outcome being predicted. Stepping on the first rung of a ladder is a significant pre-incident indicator to reaching the top; stepping on the sixth even more so. Since everything a person does is created twice—once in the mind and once in its execution—ideas and impulses are pre-incident indicators for action. The woman’s threats to kill revealed an idea that was one step toward the outcome; her introduction of the gun into the argument with her husband was another, as was its purchase some months earlier.
