It happened to all of us when we were kids: During a tense moment, some adult (Mom, Dad, a teacher, a principal, or someone else in authority) ordered us to “Take that look off your face!”
What look? I was trying as hard as I could to be completely expressionless. And, since of course I couldn’t see myself, I had no idea (and still don’t, to this day) what that person saw. Defiance? Mockery? Anger? I’ll never know.
Incidents like that one teach a useful lesson: Don’t try to guess at another person’s intentions.
That principle is especially important to report writing. Labeling a person as “belligerent,” “hostile,” “confused,” “helpless,” or some other mental state is risky. In a court or disciplinary hearing, the person might come up with a totally different description and explanation, damaging your credibility.
The rule for report writing is the same one that professional writers use (and you are a professional writer, after all!): Show, don’t tell.
So, instead of writing that she was “driving erratically,” write down what she did: Crossed the center line three times in less than a minute, or braked five times while approaching a stop sign.
Don’t write that he was “belligerent”: Record exactly what he said to you. Note the signs that signaled to you that a witness was frightened: darting eyes, trembling lips, shaking hands.
Train yourself to notice and remember what people around you are doing. That kind of practice will help you develop the descriptive skills needed for effective reports.