I skipped over telling you about Week 3. The district attorney spoke, and although it was interesting, it wasn’t all that useful for the purposes of a mystery writer.
This week certainly was. The presentation was by the homicide detectives in my local police department. I learned all kinds of useful things.
- They hate CSI and all the related shows. Hate them. Not only because they get so many things wrong, but because of the effect on juries, who expect the police to be able to tell everything about the crime from the evidence.
- The “first 48” rule is true. If they don’t identify a primary suspect in the first 48 hours after the crime, the chance of solving the case goes down to 50%.
- They never close a case until the killer is caught. Many times they know who the killer is but don’t have enough evidence to charge him or her. They don’t close those cases; they leave them open, hoping something will change.
- You cannot tell how long a body has been dead from liver temperature! That only works in controlled climatic conditions, which we almost never have here in Florida. Rain, heat, wind, cold – they all have their effect. There are too many variables to determine time of death at the scene.
- It’s blood spatter, not blood splatter. (I knew that.)
- A corpse begins to smell in about three hours, but that’s not decomposition – that’s bladder and bowel release. The smell from decomposition begins in about two days.
- It takes decades for a skeleton, exposed to the elements, to turn white. For a long, long time they’re brown. The detective compared it to a dog’s rawhide bone. (I’ll never look at them in the same way.)
- You cannot tell where a shooter was standing based on where the shell casings are found.
- Serial killers do not keep the same m.o. for their entire careers. They evolve and “perfect” their techniques.
So there you have it. I’ve made at least one mistake in already-published books, and there are probably more! I’ll do better in the future, thanks to this class.