Using Luminol to Detect Blood on Concrete Nearly a Year After Deposition

So most of you know that in addition to writing novels I also continue to conduct research in the forensic science. Some of it is probably quite boring but I thought you might find my latest paper interesting.  We wanted to see how long after deposition we could detect blood on concrete. Concrete has spread across our world at an exponential rate and to no one’s surprise, CSIs must search it frequently for evidence. Blood is generally considered to be fragile and may “disappear” from sight after a few days. We’d like to get called to a crime scene immediately but that doesn’t always happen. A previous study had found bloodstains outside on a concrete wall about two months after deposition but we thought it may be possible to detect it much later.

We also wanted to test the effects on a completely exposed surface (to the elements) with the possibility of some foot traffic.   I suspect that we could detect even older blood in a garage, warehouse, or basement floor.  We decided to use the blood reagent Luminol because of its sensitivity to blood (1:1,000,000). Luminol is a chemiluminescent reagent that has a long history of use in forensic investigations.  Here is a link to the paper if you want to read it (or need to fall asleep!).

As crime novelists I thought it might give you some ideas for a realistic scene. The technique could be used in any scene where blood may have been deposited. Some examples for your novel could include traffic accidents, drive-by shootings, or any other type of violent crime. DNA analysis would not be possible but your detective or CSI might be able to verify a statement from a witness, co-conspirator, or even a psychic! While our study used an “X” type pattern it is plausible that one may uncover footwear or tire impressions or other bloodstain patterns (like drag marks). It may be a great way to keep your reader engaged in the scene as they “discover” the evidence alongside your characters.

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About forensics4fiction

Hi there. Thank you for visiting my BLOG for crime writers. I hope you will find it interesting. I would love to hear your questions and thoughts regarding forensics and criminal investigations. I hope that the information here will help answer your questions or ignite your imagination. I am a retired senior criminalist with 15 years of forensic experience. I have served as the president of the Association for Crime Scene Reconstruction, Rocky Mountain Association of Bloodstain Pattern Analysts, and the Rocky Mountain Division of the International Association for Identification. I am triple board certified in forensic related fields and one of only 40 board-certified bloodstain pattern analysts and 80 board-certified footwear examiners worldwide In addition to writing over 60 scientific papers, I have worked as the editor of the Journal of the Association for Crime Scene Reconstruction, been interviewed by and consulted for television, books, magazines, and newspaper articles including documentaries on the Discovery Channel and National Geographic.

Posted on October 18, 2013, in General, The Crime Scene and tagged , , , , , , , , , , , , . Bookmark the permalink. 2 Comments.

  1. Hi Tom, i came across your blog while researching about bloodstain pattern analysis. I find your posts very interesting and informative. And would love to read your novels too! I have a question, for dirty or dusty shoeprints, we will use the lifting apparatus to lift the prints. And if it’s a bloody shoeprint, we will use chemical enhancement such as LCV or ninhydrin. What about dirty shoeprints created while stepping onto a vertical wall? How or what chemicals do we use to enhance them if they are not very visible?

  2. You could use an ESDL on vertical surfaces.


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