I’ve mentioned my love of crime dramas, mystery fiction and the like before. I find all aspects of it fascinating – from the reasoning behind the crimes to the people who investigate those crimes (and even the reason they chose to be investigators in the first place). I’m also fascinated by the tools and techniques used to solve those crimes. One of my favorite tools of the trade is luminol – I even like the way it rolls of the tongue when I say it. Luminol.
Some people might be wondering, WTF is luminol? Well, here are a few things that I learned during my research thus far.
Murder can be messy, and that means there will probably be blood. Some murderers will try to cover up evidence of their crimes by cleaning away the blood as best they can. Just because they can’t see the blood, it doesn’t mean the evidence is gone. Small traces will cling to fibers and surfaces. They can be there for years, invisible to the naked eye.
How does it work? Blood, more specifically the hemoglobin protein in blood, carries oxygen. When luminol is introduced, a chemical reaction occurs. I’m no scientist, so I can’t really go into the how and why of the chemical reaction. I can give you the gist though. As the molecules break down and the atoms rearrange they begin form other molecules. This process releases light energy that investigators are able to see.
The light emitted from the bloodstain will look like a blue (or bluish-green) glow. It only takes about 5 seconds for the chemical to start working and it will glow for about 30 seconds or so. Investigators will then photograph the area with the luminescence – something that can be difficult because it has to be completely dark to see the luminol. This glow can let investigators know that they are on the right track and it might lead them to other evidence or new tactics for questioning for their suspects.
The chemical can find hidden blood spatter patterns in addition to small pools and drops of blood. The spatter patterns can give detectives and forensics specialists more information on the nature of the crime including the type of weapon used. A blunt object will leave a different spatter pattern than a knife. A bullet will leave yet another pattern and so on. Knowing the type of weapon used can give investigators something new for their case.
Is luminol foolproof? Will it solve the crime every time? Nope. It is just one of many tools and it has its faults.
Other chemicals, such as bleach, can mimic the look of blood after using luminol. If an investigator sees that telltale glow, she can’t assume that it’s blood. The forensics team has to apply other tests to be certain. Then they have to see if the blood even relates to the crime they are investigating.
Another problem is that luminol can actually destroy evidence, which is why real life investigators don’t use the chemical at every chance. Some manufacturers have now made luminol that supposedly doesn’t destroy the DNA evidence.
When used properly and under the right conditions, luminol can be very effective at helping law enforcement solve crimes.
Oh, and guess what? I found out that luminol is available on Amazon. I’m tempted to try it for research purposes in case any of my characters ever have to use it (who am I kidding, it just sounds fun).
Now, all I have to do is find a butcher shop that will sell me some cow or pig blood… and that doesn’t ask silly questions. If I do, I will be sure to take pictures and let you know how it turned out.
Yeah, this is how I spend my weekends. Sad but true.
