In a lot of movies you’ll hear an attorney object because evidence is “circumstantial.” Most people, writers included, haven’t a clue what that really means.

There’s two kinds of evidence a writer should be aware of. One is what we call “direct evidence,” and the other is the much misused word “circumstantial” evidence.

What the difference between them?

Direct evidence works this way. You’re working in a building and you can’t see outside. I walk in with wet hair and wet spots on my clothing and I tell you it’s raining outside. You see the evidence of the rain and you have my statement to back it up.

Circumstantial evidence is that evidence from which we can “infer” that something happened or is happening. In this, people walk in with wet hair, rain spots on their clothing, maybe even folding an umbrella or two. Without anyone telling you anything, you can infer it’s raining outside. Your determination is based on a logical and (key word) reasonable observation of facts.

I’ve plenty of both happening in my next novel, Against Flesh and Blood.

An example of circumstantial evidence is the finding of the underwear which begins the case. Armed with knowledge of sexual assault cases and human psychology, it’s a reasonable and logical assumption on the part of RJ that something happened when the underwear was discovered (humans normally don’t leave their underwear lying about).

The evidence to support that something occurred is when Will and RJ find the crime scene and process it. The personal effects, tire prints, and tire tracks all infer that something more happened, and that this is where it happened. From reading the tracks, Will is inferring what occurred and how. Again this is based on logical deductions based on experience and skills.

Up to this point, almost everything points towards a crime that hasn’t been reported yet. Will and RJ are moving forward believing that one will be, and they treat the crime scene as if that will happen.

The idea with circumstantial evidence is that it builds a net around the perpetrator. One of the most critical pieces is the partial license plate tag. From this, Will is able to identify three possible vehicles that fit the description the girls gave. Again, a logical and reasonable assumption.

During the course of the interviews, additional evidence is generated. One direct piece of evidence comes from one of the girls. She correctly identifies the type of weapon the perp used. How? Her father owns one just like it, and she’s used it to kill rattlesnakes. Direct evidence – she saw it and knew what it was. She didn’t need to infer anything about it.

A sketch of the perp is made and distributed to the paper and into local stores and stations. Different individuals then give leads showing that an individual who meets that description was in the same area where the girls were.

The entire case could have been solved using nothing more than circumstantial evidence. The final piece of direct evidence was simply the final nail in the coffin of our perp, and I won’t give that away yet.

Next time, we look at the crime scene and the tactics used to process it.