Crime Scene investigation for writers who want to make real crime books.
Let me start off by saying, throw everything you've seen on CSI out the window. The real CSI's of the world DO NOT interrogate the suspects, DO NOT sit back in the lab and sift over each piece of evidence. So, with that out of the way, we can start.
The initial black and white will assess the scene, call it in to dispatch, and then seal off the scene to keep onlookers and the curious out of the area. A single entry point will be determined. No one enters or exits the scene other then by this entrance. Other then sealing off the scene, the uniformed officer's job is done-it becomes the CSI's scene.
One the detective arrives, he or she takes over the crime scene and everyone answers to them-including the CSI technician.
The CSI tech sifts through the scene, collecting the evidence and storing it in ways to preserve what is found. It's no glamorous, because on every murder, the CSI will spend on average 12 hrs on scene before leaving. Once the evidence is bagged and tagged, if it needs further analysis-as in DNA/Ballistics, or Forensics, that is handled by a Forensic Pathologist, and the CSI is out of the line until possibly being called into court. Most of the heavy lifting in analyzing the data if done by the pathologist's and scientifically trained crime scene analysts.
However, without the CSI, they wouldn't have the evidence to work with, so he or she will cover the scene in fine detail. There are two to three different ways to work a scene. You can go back and forth from top to bottom. The second is to use a spiral search, and the third, which is my favorite, split the scene into four quadrants, and search every inch before moving on. This method assured you of the best chance of collecting all the evidence.
Sometimes the job gets nasty too. If the DNA evidence is found through poop-guess who is grabbing it from the toilet?
The thing to remember about violent crime scene investigation (and in fiction if you want to be realistic with crime novels and/or mysteries) it's not about WHAT is at the scene. it's about WHAT IS NOT there. As to how things go further from there, I'm not at liberty to say.
Bullets. Each shell his it's own unique pattern caused by the rifling in a handgun's barrel. Rifling is a spiral shape cut into the metal of the barrel, which gives the shell a spinning pattern, increasing distance and accuracy. That's why rifles are called rifles-they started it, and handguns picked up the pattern later. As mentioned before, they have their own patterns and can be compared against the FBI database in Quantico, Va. for matches. Since 1995, all handguns, and rifles, for sale in the USA has to have two test fired shells since to the FBI. This allows for rapid identification of the type of bullet and handgun fired from. Once that's determined, it can be matched (can't say the ways how) with the firearm it was fired from.
Bodies. Ok, this is where things get gruesome, so if people have weak stomachs, this is when to stop reading.
Ok, if you're still here, then you want to know more. Good, here we go. We'll start with corpse's found in the water. If any human body spends more then 24-36 hrs in the water after death, it will do two things. First the body will bloat from absorbing the water. The second, is it will turn coal black. Odd, I know, but it's what happens. It is impossible to determine race, and sometimes gender, by looking at it when collected. The forensic pathologist (called medical examiner also) has to run various tests before it's determined.
Gun shots. These are the tricky parts. Some shells will go all the way through, no matter where fired, and some won't. A .38 shell, believe it or not, depending where it's fired can stay in the body. One gunshot death I know of, the weapon was fired near the vic's (victim's. I'm using slang) neck ended up going into the brain, bounced off the top of the skull and lodged into the cheek. It was removed by feeling the skin back to get it. Ok, each gunshot wound leaves power burns called stippling. A shot fired in contact with the skin will leave a good amount of burns around the wound. Medium range shots (less then ten feet) will leave spotty residue around the wound, and a long distance shot leaves little if any. This is a determination of how far the shooter stood.
Not all gunshots behave the same. A shotgun does little damage, figuratively speaking, when it enters the head on a suicide, but will blast skull outwards.
Overdoses. Depending on drug, are mild scenes to see. Chris Farley, when he OD'd, expelled a large amount of stomach acids, which covered his mouth. Those are seen quite often in overdoses. You can find his scene on google.
Stabbings. By far the worse of the violent deaths. There's tons of blood, and spray. The spray, how high and far, determines how much pressure was involved when the fluids were released. A good example of this is the OJ Simpson murder trial. When he (I know the jury didn't convict, but that's due to screw ups by the LAPD. I've seen enough evidence that got tossed from court to prove he did it 100 times over. Trust me on this one.) Death photos are on google, and they're gruesome. More blood is lost through stabbings then anything else.
Industrial accidents. They're not pretty and range from getting caught in machinery, crushed, or hit by a train. Those, you'll just have to use your imagination on.
Time of death can only be estimated. Unless you're looking at the clock at the exact moment someone dies, there's no way to give an exact time. So, the comments on the TV that say exact times are inaccurate. Various factors such of body temperature, and how long it's been since being found, will determine that to a point.
Rigor Mortis. It starts several hours after death, and stays for a couple days before going away again. It's not a permanent condition.
Bodies found in the ground, will most of the time, be covered in maggots. It's the way of nature, I'm afraid.
This is all I can say on the subject. Hope it helps.
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