What the Heck is Entomotoxicology?
The House fly
I’ve written before about the role of the forensic entomologist in death investigations. These professionals can provide critical information regarding the time since colonization and postmortem processes. One aspect of their analysis that is being utilized for frequently is the use of insects (like maggots) to screen for the presence of drugs or toxins (like Malathion). Before I get into the process, let’s discuss why this type of testing might be undertaken. Obviously, the presence of illicit drugs like cocaine, heroine, MDMA, or amphetamines, may provide critical information about a possible cause of death, criminal activity, and victimology. In the same light, the presence of prescription drugs may also shed light on the victim and their physical or mental health. Likewise, the absence of certain drugs may also reveal important clues surrounding the victim’s state of health. Did they need the medication to maintain a certain quality of life or health status?
Why not just review their medical records? First, the victim may not have a complete documented medical history. Some people gain access to prescription drugs through illegal or unethical means. Family members (even spouses or parents) may be unaware of certain health conditions. Additionally, the victim may not be identified at the crime scene. Insects like maggots can removes significant biomass during the decomposition process and some victim’s don’t have any identification on them. We may be able to extract DNA but that will be of little help if their profile is not on file. We may be able to construct certain features or details about their lives based on their physical possessions (clothing size, piercings, tattoos, etc.) but the presence of certain drugs or toxins may provide that extra clue that helps to narrow down missing person profiles.
The concept of using insects for drug screening is pretty straight forward. While the victim’s tissues and fluids (blood, urine) degrade through decomposition; the larvae do not. In effect, they act as mini-reservoirs. Eventually they will undergo some kind of metamorphosis but if they are found on a body they can be tested. As adults they tend to eliminate the toxins rather quickly but even trace amounts of some drugs have been found in recently emerged adult flies. Some research has even detected drugs in beetle frass (excrement) and fly puparia years after death. Testing is begun by crushing or grinding the insect samples in something like a mortar and pestle. There are a number of different tests that can then be performed including Gas Chromatography / Mass Spectrometry (GC/MS), Fourier Transform Infrared Spectroscopy (FTIR), and radioimmunoassay (RIA). In many ways the testing sample is treated like any other biological tissue. The effects of various drugs and toxins on the rate of biological development (of the larvae) is not fully known. These types of exams primarily screen for the presence or absence of drugs and toxins. The effects of such substances on insect biology is another matter the entomologist must consider when estimating the postmortem interval.
As authors you may consider using insects as a testing source for drugs or toxins, especially when other tissues are not viable. Consider too the absence of certain prescribed drugs that may affect the victim’s behavior or general health. The drugs may be illegal or they may have been stolen by the suspect from another family member, friend, or co-worker. The presence or absence of drugs or toxins may also reveal a “unique” data point in the unidentified victim’s profile to compare against missing person’s records, medical records, or even criminal modus operandi (such as the use of a date rape drug or poisoning by mercury). You probably already have an interesting application of drugs or toxins in your storyline. The use of insects to test for those substances will provide for some interesting dialog between characters or plot twists for your readers.
An Experiment in Observation
The art of observation is critical to every CSI. We have to be able to see things that others can not. Contrary to popular opinion we don’t always “see” everything that we see. To steal an example from Sir Arthur Conan Doyle; close your eyes and say out loud how many steps it takes to get from your bedroom door to your kitchen. Easy right? I mean, you probably walk that route several times a day don’t you? Why would you have trouble describing the number of steps it takes? It’s the difference between “seeing” and “observing”. We may see things but we may not observe them.
As authors, we have to describe scenes for our readers. We have to do it in such a way that they feel a part of the scene. This is easier when we feel a part of it ourselves. I’m sure you’d agree that your writing is much better when you’re describing a place you’ve actually visited. But even if you’re familiar with the setting…how well do you really know it? Here is a simple exercise to help you develop your skills of observation. The more you practice such exercises the more vivid and detailed your scene writing will likely become.
Where ever you are right now, get a sheet of paper and a pen. Pick a room on the other side of your home (or your office). Imagine yourself standing in the doorway facing into the space. Now I want you to describe the room. Start on your left and begin writing down everything I would see if I were standing where you are. Spare no detail. Give yourself ten minutes to complete the task. Then try to draw a “birds-eye” diagram of the furniture in that space. When you’re done, take the notes and diagram to the room and see how you did. Did you capture all the detail? The colors…the sounds…the smells?
If you live in a dorm room or one bedroom apartment you can try something a little different. Think of a picture in your place of employment or relatives house. Got it? Now describe it and draw it. What are the colors? How many elements (people, animals, buildings, etc.) are in it? What color is the mat board? How about the frame? Where is it on the wall?
I’m not suggesting that CSIs have photographic memories. We don’t observe everything either but, we develop our skills of observation to “see” more than the average person. I’m betting that, as authors, you see more than you think; more than most others. Exercises like this are what we use to train new CSIs to observe details others may miss. I hope that you’ll find it an interesting first step in enhancing your observation skills.
Understanding the CSI Mindset
Today I was invited to guest blog at Criminal Lines about keeping the CSI character “in character”. Stop by and check out her BLOG and other great articles!
Hidden Paths to Hidden Worlds
I love being out in the woods. I don’t mind walking established trails but it takes no convincing to get me “off trail”. One of the reasons I love getting off the beaten path is that I get to see things most people don’t. Wild critters, small brooks, or hidden canyons. I sit and wonder how long it has been since another person was seeing what I’m seeing.Most of the time I’m not that far away from the rest of those enjoying the outdoors. Maybe just over a hill or around a bend but, it makes all the difference in the experience. I often think “wow”, I would have never seen that bear, bobcat, or elk if I hadn’t come this way.
In the modern world we’re conditioned to follow certain paths. Sidewalks, roads, green belts, subways, etc. Think about it…don’t you take the same path to work everyday? What about the grocerie store, gas station, or your child’s school? Partly this is because we’ve determined the easiest, most efficient, route. But even when you’re going somewhere new you generally stay on some kind of path right? Don’t most of you hesitate to cross open space unless there is a trail? Even then, if there is a sign prohibiting it, most people won’t. This type of thinking limits the world we see and experience. Criminals aren’t restrained by thinking.
One of the toughest things to learn as a new CSI is to stop thinking like everyone else and start thinking like a criminal. You have to divorce yourself from even the most basic and accepted thoughts. Criminals have to conduct their “business” and get from point A to point B but, some of them don’t want to draw attention to themselves (just like animals). At least the successful ones don’t. They like to conduct their business in the “shadows” or “off the beaten path”. There is a whole world of activity going on right now…off that beaten path. These are worlds within worlds and it is the job of the CSI to find them (at least as they pertain to criminal activity).
These are places where most of us have no reason to go. Culverts, abandoned buildings, tunnels, and over grown gulches. Sometimes these places are right under our noses. I remember being a young officer and getting a call about a “satanic” alter being found at a movie theater. Turns out there was a “hidden” room above the concession stand but below the projector room. In the old days they used the room to cut film reels. It hadn’t been used in decades for that reason but someone was using it now. There was no way to tell how long it had been in use but that’s not my point. The point is that the activities were going on right under everyone’s noses because no one ever had reason to go in there. The room was “off limits”.
Don’t forget about these “hidden worlds” in your writing. I’ve made it a point in my novels to include such places and I think it adds a powerful layer of mystery to the settings. These places are even more frightening when your characters stumble upon them for the first time. It may be a detective, teenage runaway, or concerned parent. The possibilities are endless and can be driven by the structure itself. The video below is apparently from an old missile silo. Imagine the types of crimes that could be going on in such a place and how hard it would be for someone to stumble upon it? Might be a good idea for a novel eh?
Interview with Forensic Geologist Jim Reed
I have a special treat for you today F4F readers. Jim Reed is currently the Director of Research & Development for RockWare Incorporated, a geological software company based in Golden, Colorado with a European office in Lugano, Switzerland. Jim began studying geology at the University of Wyoming and ended up at Washington University in St. Louis, Missouri. His career as a geologist began in 1973 when he worked for NASA on the Mars Viking Lander project while moonlighting for Arch Minerals computing coal reserves in the Illinois Basin. He then went on to work as a project-level field geologist for Freeport Exploration (copper, gold, silver) in the Mojave Desert and southern New Mexico. From there, he became a regional-level field geologist for AMAX Exploration (molybdenum) in the Sierra Nevada of Northern California and the Trans-Pecos regions of southwestern Texas. He then became a senior geologist at Wold Minerals (uranium & talc) based in Austin, Texas. Since founding RockWare in 1983, Jim has worked in China, Africa, Cyprus, Russia and Papua New Guinea. His expertise includes environmental site contamination characterization, hydrogeology, mining, petroleum, and geotechnical volumetrics (computing the shape and mass of buried objects). I have known and worked with Jim for a number of years in NecroSearch and he’s the real deal.
F4F: Tell us a little about how you first became involved in forensic investigations?
REED: About 20 years ago, I got a call from Clark Davenport, a crazy geophysicist and soon-to-be mentor and lifelong friend, who was one of the co-founders of NecroSearch, a newly-formed, non-profit organization made up of volunteers from a variety of disciplines, many of which I had never even heard of. Entomology? What’s that? They were looking for a geo-nerd to apply geological software to their investigations. The timing was perfect because I was looking for something civic to become involved in. So I showed up at their next meeting and was absolutely captivated by the idea of working with real cops on real crimes. As a kid, I was always in trouble with the cops, so this was my chance to flip things around. Personal computing was fairly new at the time so I was considered a god. Nowadays, everybody in the group just thinks of me as an obnoxious computer geek.
F4F: Can you tell the readers the difference between forensic geology and geophysics?
REED: Geophysicists are just geologists who could pass calculus and physics. Geophysics always involves complicated-looking electronic gizmos with lots of blinking lights that measure things like soil conductivity (e.g. moisture) using outrageously simple concepts that are disguised by fancy jargon. I’m not exaggerating. Really. Consider a “resistivity” survey. Connect a wire from the positive end of a battery to a voltmeter. Then run a wire from the other pole of the voltmeter and stick it into the ground. Run a wire from the negative side of the battery into the ground, and voila, you’ve got a “resistivity meter” or a “soil conductivity meter”. By comparison, geologists are typically limited to rock hammers, colored pencils, and a compass, albeit a fancy compass. The term “forensics” has been muddied over the years to essentially apply to any endeavor that involves lawyers. If somebody’s house slips off its foundation, the homeowner’s attorney may hire a “forensic engineering geologist” to testify in the lawsuit with the contractor. The forensic engineering geologist, as opposed to a plain ol’ engineering geologist, knows to look at the jury and the judge when he/she answers a question rather than looking at the person who asked the question. That’s about it. In regards to crime-fighting, I consider a “forensic” prefix to mean that you know how to conduct yourself at a crime scene (drinking coffee, eating donuts, and swapping jokes), collect evidence, and provide expert testimony at the trial.
F4F: Most, if not all, forensic geologists are employed by private industry or universities. What do you see as the biggest challenge for a geologist working a forensic case for the first time?
REED: Wow, “for the first time”? That’s tough. I think the biggest challenge is to act like you know what you’re doing. Seriously. You may be at the top of your game geology-wise, but I can guarantee that you’ll fall apart on your first case. Here’s why; methodical, well-planned field methods fall apart when Channel X turns on the bright lights, sticks a microphone in your face, and the cutie asks a question that is so outrageously stupid that your brain locks up in an infinite loop, unable to come up with an answer that doesn’t come off as smartass, condescending, or extremely nerdy. In the end, you just come off as an idiot. Most geologists are used to working in remote locations by themselves where there’s nobody to see you screw up the first three times. It doesn’t help when you overhear law enforcement guys laughing amongst themselves, saying “Damn, I could have dug up this site with a backhoe in the time that it’s taking that geo-guy to figure out his GPS.” My advice to a geologist who’s working their first case is to find a mentor and mimic their every move. Another problem is that most science curricula beat young students over the head with the concept of the “observer effect” which essentially states that you can’t measure anything without effecting the outcome of the experiment. On a crime scene, the geologist becomes overwhelmed with this principle. How can I measure soil compaction if all of these crimes scene technicians are stomping all over the place?
F4F: What are some of the most effective technologies in remote sensing for law enforcement in your opinion?
REED: Oh boy, how much space do I have to answer this one? Well, let’s start with the least “invasive”, meaning techniques that don’t screw up the crime scene. First off, there’s conventional satellite imagery. Google Earth is the starting point, especially if you use their historical imagery capability to compare images before and after the date when the evidence was buried. Next comes higher-resolution imagery, typically from the local tax assessor or the utility companies. An infrared camera is a great tool because you can look for ground that has a weird thermal “signature”. I don’t mean ground that’s glowing with heat because a body is decomposing, but rather subtle differences related to how the disturbed soil is heating up or cooling off during a 24-hour period. From here, we start in with the geophysics, measuring things such as soil moisture because anybody who’s ever planted a garden knows that turning the soil increases its ability to hold moisture. Then comes ground penetrating radar (GPR) in which we’re looking for disturbances within the natural layering of the soil layers. If there’s reason to believe that ferrous metals (anything that can rust) are buried along with the victim, we might use a magnetometer which measures the magnetic field produced by elements such as iron. An invasive gizmo called a “cone penetrometer” can be used to measure the compaction of the soil. This is essentially a very expensive metal rod that you push into the ground. The penetrometer measures the pressure required to push the rod point to various depth levels. Once you start in with these types of “geo-technical” tools, you’re disturbing the site, so it’s import to start with the least invasive methods and then progress towards the destructive. Sort of like medicine. Start by asking about the symptoms, suggest some changes to diet, exercise, etc. before you pull out the scalpel.
F4F: I can’t think of anyone that has used technology more effectively to advance our abilities to locate clandestine graves. Can you talk about how you’ve adapted RockWare technology to forensic science?
REED: Thanks. I’m blushing. Mostly, I’ve added a bunch of programs to RockWorks for merging the data from the different disciplines and boiling it down to a single target. This means “normalizing” the data from the botanists, the remote sensing (e.g. thermal), geophysics, etc. so that we can compare apples with apples. The next step is to “standardize” these spatial (map) data sets such that they’re expressed in terms of “standard deviations from the mean”. That’s a fancy way of saying that we’re converting the data to units that represent weirdness relative to undisturbed terrain. Finally, these programs boil all of this disparate information into a “dig here” map. The technical terminology for this type of analysis is “N-dimensional, multi-variant, weighted spatial analysis” – a great term to throw out when you want to intimidate a cross-examining defense attorney. Another big improvement, thanks to the on-site forensic experience involves ease-of-use. It’s one thing to write a program that you can use if you’re sitting in a quiet office with the luxury of silence and a user manual. It’s another thing to create an interface that is useable on the hood of a squad car when everybody around you is making you nervous. We’ve also added one-click export to Google Earth thereby eliminating the coordinate conversion hassles that drive investigators away from computers.
F4F: You worked on high profile cases all over the world. What was your most memorable experience?
REED: There have certainly been some cases that impress my friends, like going to Russia to look for Anastasia Romanov, but the ones that I remember the best are the ones that I’d really like to forget. Don’t get me wrong; the rewards from this type of work are profound. Directly helping to put the boogie-man away, providing “closure” to family members, working with world-class scientists, befriending some of the greatest law enforcement people – these are the some of the many benefits. But … in the last few years I’ve been paired up to work side-by-side, in the field, with cooperative perpetrators including serial murderers. Being nonchalant and friendly with these guys has taken a toll. In one instance, I left the group for about a year until the nightmares went away. Eventually, I realized that there was a hole in my life that NecroSearch filled so I became active again and sure enough the nightmares started right back up. The difference is that I now accept them as “normal” costs well worth the benefits. Part of the job.
F4F: You’re on the forefront of new technology. What do you see emerging in the next five or ten years that may help law enforcement find clandestine graves?
REED: Ground-based LIDaR (Laser Imaging Detection and Ranging) is going to absolutely and unequivocally revolutionize crime scene investigations. Most law enforcement folks haven’t even heard of it yet, but trust me, it will change everything. Here’s how it works; You arrive at the scene, set up a tripod, mount a clunky gizmo on top, turn it on, and walk away. The LIDaR laser/camera sweeps up and down while rotating, recording the location and color of everything at the site. Every blade of grass. Every twig. Everything. You pull out the memory card, plug it into a laptop and you’ve got a color “point cloud” that exactly reproduces the crime scene in three dimensions. Right now, LIDaR is incredibly expensive, but so was GPS twenty years ago and now every cop has one. For NecroSearch, I see LIDaR allowing us to create micro-topographic surfaces that will show the slightest disturbance (e.g. subsidence). Anybody who has ever visited an old graveyard knows what happens to the ground surface over time. You don’t even need to bury something to create a topographic “anomaly” – just dig a hole, backfill it, and return in a year. You may now be able to see it, but LIDaR will.
For more information about RockWare and their flagship product, RockWorks, visit: www.rockware.com
Interview with a Forensic Botanist: Dr. Jane Bock
Dr. Jane Bock is a forensic botanist and researcher from Colorado affiliated with a number of professional organizations. She has been conducting field research for over four decades and has received numerous awards including the Ralph W. Schreiber conservation award and Hazel Barnes Prize. I first met Dr. Bock while working in NecroSearch International. She has worked numerous murder cases across the nation and is very approachable for those seeking additional information. The field of forensic botany is fascinating. From looking at last meal evidence to disturbances from burial, plant material can provide great insight to an investigation. If you’ve never thought of including botanical evidence in one of your novels you might reconsider after reading this interview. Her new book Handbook of Forensic Botany will be released this year.
F4F: Historically, how long have plants been used in forensic investigations?
BOCK: Forensic botany reaches far back in Western history. Plato, in his writing (Phaedo 399 BCE), describes the suicide of his teacher, Socrates, in detail. Socrates chose to commit suicide by imbibing poison hemlock (Conium maculatum). Plato’s description of Socrates’ symptoms fits exactly the pattern of poison hemlock poisoning today in the US and Europe. Forensic botany became ‘scientific’ with the inventions of the printing press (1440 AD) and the light microscope lenses (1590 AD). Using a microscopic lens, Robert Hooke described the cellular nature of cork cells, later published in his book, Micrographia. The earliest books describing plant cell types followed shortly. Forensic botany came of age in the US in 1934 when botanical evidence was used to solve the kidnapping and murder of Charles Lindbergh’s baby boy.
Botanical evidence in courts today is accepted readily through both Frye and Dauburt examinations provided the witness shows competence in botanical knowledge. My cases have involved knowledge from three subdivisions of botany: plant anatomy, plant taxonomy, and plant ecology.
F4F: How are plants used in last meal evidence analysis?
BOCK: Dr. David O. Norris and I fostered the identification of food plant cells in criminal investigations and trials. Plant cells usually are enclosed in cellulose walls. These complex carbohydrate walls are virtually indestructible. They pass through the human digestive tract unchanged in their sizes and shapes. It does not matter if the plant was consumed raw, canned, frozen or cooked. Each food plant has cells that are distinctive in size and shape. We commonly examine plant cells from stomach contents. There is a rough time table for how long each stage of the human digestive process takes, and the time for stomach digestion usually is within a couple hours of consumption, then the material passes to the small intestine. This can be helpful in some homicides in estimating the time of death.
Identifying food plant cells from the digestive tract and feces of a homicide victim may link the victim to a certain place where a meal was taken and may link a suspect’s presence to that same place. Two recent cases involved the plant foods found in the stomach contents of people whose exact diets were known (hospital and prison). When the records of the day’s meals were compared with stomach contents, we learned which meal was the victim’s last even though a suspect claimed the person had been killed after a later meal.
F4F: What are the most common types of analysis you’re asked to conduct for law enforcement?
BOCK: Plant Taxonomy: assigning the correct scientific plant name to a plant or plant fragment. Such identification can link a victim to a suspect through plant fragments found in clothes or vehicles. Such evidence also can show a place where a victim and/or suspect visited. what residences These cases are relatively common. Plant Ecology: the relationship between plants and their environments. Here, you test ideas about where plant materials originated. In a case, a truck contained fragments from a mountain setting, but the trucker claimed the vehicle never had left the prairie. This along with other evidence led to a murder conviction.
F4F: Some of the readers may be unaware of the use of pollen, seeds, and diatoms in forensic investigations. Can you talk a little about how they may be used to link a suspect to a crime scene?
BOCK: Most plants are made up of stems, roots, and leaves, plus reproductive parts (flower parts and seeds). These all have cellulose cell walls. However, other organisms have cell walls comprised of other substances. These plant structures can fall into the forensic botanist’s purview, and include pollen, spores, and certain microorganisms. The presence of pollen in association with a cold case homicide can suggest a season when a crime took place because the shedding of pollen is highly seasonal. Diatoms have cell walls of silica and are virtually universal in all bodies of water from mud puddles to oceans. However, species distribution and relative abundances among species have given strong evidence of the source the water in a case. Here, the water in the victim’s lungs indicated that he had been in a body of water that was distinctive from the location described by the suspect.
F4F: You’ve been involved with a number of high profile murder cases over the years. Is there any one case involving plant evidence that really stands out to you and why?
BOCK: High profile cases can be difficult if the media have publicized widely their decision about guilt. For example, in the defense for the Casey Anthony case, making trips to the courthouse involved running a gauntlet of reporters and other supporters of a guilty verdict yelling my name. Also, e-mail threats for the expert if you are involved with the ‘unpopular’ side. The most renowned high profile murder case I’ve worked occurred over 10 years ago and has not been brought to trial. Therefore, it is an ongoing case and my evidence cannot be discussed here. This continues to weigh heavily on me because of what my partner and I know from our evidence. In a recent cold case in Pennsylvania where the victim was an 80-year old woman, we determined the contents her last meal. It had served as the medium for the poison that killed her. We supplied a deposition and this led to a confession of the persons who killed her. Had it gone to trial it would have been very high profile.
F4F: What’s on the horizon in forensic botany? Are there new technologies that are poised to open areas of inquiry that were previously unknown?
BOCK: A worrisome aspect of this field is that it is underutilized and under represented. The approaches described above are simple, inexpensive, and readily accepted in courts. Many more people with forensic interests must train themselves in botany. DNA can be useful in forensic botany, but our lab does not deal with it. It is not especially useful in plant identifications because there are at least 300,000 plant species., and most of their DNA patterns are not known. What DNA can do is link plant fragments from a single plant to a suspect to a victim, to a vehicle, to a place. This works well. DNA analysis is being streamlined and will become more so. Already some kits are showing up so that a major laboratory may not be required.
I am happy to discuss forensic botany with interested individuals, and also to point them to appropriate scientific literature.
A New Forensic Resource Website for Writers!
I was just informed about a new resource site for basic information about the forensic sciences. I’ve looked it over a bit and it seems well done. I think the real benefit will be for those non-scientists needing a starting point to understand a particular forensic discipline. The site is called forensicsciencesimplified.org and is run by the National Forensic Science Resource Center in Florida. The home page is very well organized. You simply find the tab for the discipline you want to explore and click on it. Once inside you’ll have options to read about the basics of the science, frequently asked questions, common terms, and common misconceptions, among other topics. They even have additional references you can link to for more information. There doesn’t seem to be a place to ask questions but I suppose you have me for that. In any event, I think it would be wise to bookmark this site. It seems well suited for authors, especially those with limited knowledge of forensics.
The National Forensic Science Technology Center has also launched a YouTube channel to share short videos of forensic science updates. Check out the latest update below and peruse the otehr videos as well. I think you’ll find it informational and a little entertaining too.
MacGuyver Forensics: Carbon Paper Shoe Lifts
Papers on the floor in a crime scene
Real life CSIs sometimes have to find innovative ways to capture evidence. There are a ton of commercial products available for nearly every type of evidence but Murphy has a tendency to rear his ugly head at the most inopportune times (like a homicide scene). Cameras break, your partner forgot to re-stock supplies, or you simply run out. In most cases you can’t just run down to the local Walmart and pick up exactly what you need. Good CSIs learn to develop alternative methods of collecting and preserving evidence (if possible) in the event you need to have a fall back plan. Some purists may scoff at such an idea but in my opinion it’s better to have something collected than nothing collected. The need to use unconventional collection methods is probably more likely for your private detective or amateur detective character. These folks may not have an impressive array of CSI gear because they don’t have to concern themselves with those matters often.
I’ve noted before that footwear evidence is one of the most commonly overlooked categories of physical evidence at a crime scene. Some of that is due to a lack of training, lack of awareness, or simply not having the proper equipment. In real life, the crime lab isn’t called to every crime scene. Usually we just go to the major scenes. Patrol officers don’t carry around electro-static dust print lifters, alternate light sources, and other specialized equipment so sometimes footwear evidence gets overlooked. One of the better surfaces to find two dimensional footwear impressions at crime scenes is paper. Paper may get scattered on the floor during a ransacking or it may just be trash on the floor (like in a warehouse). You can even find these dust prints on broken drywall, carpeting, or doors that have been kicked. Either way it can hold valuable clues. These impressions can be latent (invisible) and need some degree of processing to make visible again.
So what is your amateur detective to do when he/she spots a sheet of paper at the crime scene and thinks there’s a footwear impression on it? One simple process is to use blue carbon paper to make a lift. For some reason, black carbon paper isn’t as good. The process is really quite easy. You start by taking the paper evidence and securing it to a hard flat surface. Taping the corners works well. Then you lay a sheet of blue carbon paper down over the area you think may hold the dust print. Cover that carbon sheet with a manilla file folder or pad of paper and use a 4″ rubber roller to “press” the dust print onto the blue carbon paper. Simply roll the rubber roller firmly back and forth over the area a few times to transfer the image.
Carbon paper over print on newspaper
Using a roller to transfer the impression to the carbon paper
Once that is done the detective can flip over the carbon paper and use a strong oblique light (like a flashlight) to see the image in a darkened room. Any windowless room (like a powder room) works well. Voila! The invisible shoe print is now visible. It may be possible to individualize an impression to a particular shoe but even knowing the make and model of the shoe can be helpful in an investigation. If your prime suspect only wears Nike and the shoe in question is a cowboy boot you may need to search for another suspect right? In the end, a professional CSI would probably get better results using a gel lifter or ESDL but keep this trick in mind when writing your scenes. If your “detective” is unprepared then this might be a good option to recover evidence others may have missed.
Interview with Criminalist/NYT Best Selling Author Lisa Black
Real life criminalist and New York Times Best Selling author Lisa Black is back for a visit about her new book Blunt Impact. Lisa Black spent the happiest five years of her life in a morgue. Strange, perhaps, but true. After ten years as a secretary, she went back to school to get a Bachelor’s degree in Biology from Cleveland State University. In her job as a forensic scientist at the Cuyahoga County Coroner’s Office, she analyzed gunshot residue on hands and clothing, hairs, fibers, paint, glass, DNA, blood and many other forms of trace evidence, as well as crime scenes. She had her life sorted out just the way she liked it until her husband got fed up with Cleveland snow and moved them to Florida, 1400 miles away from her family and her career. Not that she’s bitter or anything. Now she works as a latent print examiner for the city of Cape Coral, Florida, police department, working mostly with fingerprints and crime scenes. Lisa has lectured at writer’s conventions and appeared on panels. In her life as a writer she’s a member of Sisters In Crime, Mystery Writers of America and International Thriller Writers. In her life as a forensic specialist she’s a member of the American Academy of Forensic Scientists, the International Association for Identification, the International Association of Bloodstain Pattern Analysts and is certified by the American Board of Criminalistics. She has had over 741 hours of instruction in forensic topics and has testified in over 50 trials. I want to give a special ‘thank you’ to Lisa for taking time out of her busy schedule to answer some questions for the F4F readers.
F4F: In the world of crime writers you’re a bit of an anomaly in that you are a professional criminalist by day. I love your tag line murder is my day job. As a writer, can you tell us a little about your process. Is is hard to find time to write when you’re working full time and on-call as a forensic scientist?
Lisa: Yes. Luckily I write relatively fast, and I have no children and very little social life (!) so I have plenty of time. I work 12 hours shifts at the police department which means I only work 7 out of 14 days.
F4F: I’m sure your day job provides plenty of inspiration for your stories. What else do you draw from when creating scenes, characters, or story ideas?
Lisa: I poach characters horribly from movies and TV–funny, minor characters, or secondary characters who interested me. Then other ideas just pop into my head and I have no idea where they come from. It’s a huge mix of various pipelines.
F4F: Crime scene investigation can be a physically and emotionally taxing profession. You’ve got the technical side nailed down but are there any topics you find emotionally difficult to write about?
Lisa: I don’t get emotionally involved in much, but there’s a few things I’m squeamish about–I can’t do anything horrible to a child or an animal unless it’s way, way ‘offscreen’. I can’t stand days of torture and buckets of blood. I’m an incredible softy when it comes to the elderly, so I can’t say much of what I’m feeling when it comes to aging parents, even though I should tap that reservoir.
F4F: In your current novel Blunt Impact, your heroine Theresa MacLean has to face some new challenges in protecting a child who witnessed the murder of her mother. Can you give us some insight on Theresa’s character (morality). What makes her tick?
Lisa: Theresa’s got a very firm sense of right and wrong, and a very firm habit of keeping her thoughts to herself. So even though she doesn’t say so, she’s a much stricter judge of other people, and especially herself, than others might guess. People make the mistake of thinking quiet equals timid, and find out the hard way that when Theresa knows she’s right, she simply will not budge.
F4F: Blunt Impact deals with a controversial new jail as a murder scene. Can you give us a taste about what makes the jail controversial and how inter-agency relationships might impact the investigation?
Lisa: The new jail is controversial for two different sets of reasons–one, because a historial Beaux Arts building is torn down to build it, so the historians are outraged, and two because it’s designed to keep inmates safe–from each other–so civil rights activisits are outraged. But the inter-agency conflicts do not dwell on these two areas, but on the money trail and where it leads.
F4F: What’s in the future for Theresa?
Lisa: The next book, titled The Price of Innocence, will be out in November and features a quirky genius, a mysterious man and a twenty-year old college tragedy.
Blunt Impact will be available April 1, featuring forensic scientist Theresa MacLean and a series of murders surrounding a skyscraper under construction in downtown Cleveland. The first to die is young, sexy concrete worker Samantha, thrown from the 23rd floor. The only witness is her 11 year old daughter Anna, nicknamed Ghost. Ghost will stop at nothing to find her mother’s killer, and Theresa will stop at nothing to keep Ghost safe.
Also, Kindle owners can find a bargain in my new book The Prague Project, written under the name Beth Cheylan. A death in West Virginia sends FBI agent Ellie Gardner and NYPD Counterterrorism lieutenant Michael Stewart on a chase across Europe as they track stolen nukes and lost Nazi gold, hoping to avert the death of millions of people.
Back Spatter from Gunshot Injuries
Back spatter can also travel down the barrel!
There are basically two types of blood spatter; forward and back. Notice I didn’t say “splatter“. Blood spatter is caused when an object impacts a body and forces the blood to break up into smaller droplets. The majority of these droplets are then projected either forward (with direction of force) or backward (opposite the direction of force) essentially. Generally speaking, there is more forward spatter than back spatter in an incident and the blood will disperse in a “cone effect”. The amount of back spatter is dependent on both the energy of the impact and the amount of blood already present at the impact site. For example, a gunshot can create back spatter even when there is no preceding injury. This is influenced by other factors too though. Clothing can “trap” much of the back spatter depending on the type and layers of clothing and location of the wound. If the wound area is not covered with clothing (like the head) then you can see more back spatter. CSIs commonly see some degree of back spatter on the shooting hand in gunshot suicides with head wounds.
The degree of back spatter on the subject varies wildly though. A number of factors influence the deposition of the blood such as subject and victim body positions, wound position relative to subject, distance between subject and wound, the amount of energy causing the spatter, intervening objects (like shooting through a window), and the presence or absence of blood at the impact site just to name a few! The size of the resulting blood droplets varies too. Gunshots and explosions can produce very tiny droplets (with a diameter of 1mm or less) while other impact events can produce larger droplets from 2mm up to 10mm and even larger. You may find back spatter on hands, faces, ears, hair, clothing, weapons, furniture, or practically anywhere near the impact event. It can even be found on items that have been moved to another room (as in a staging). With gunshots, you may find spatter up to four feet from the impact site. In theory, you could find them even further away if there is sufficient air current such as high wind or even the close proximity of a fan.
So how would you use this in a novel? Back spatter can be washed from hands and clothing or even the victim (think of a dog or cat licking the victim). Tiny spatter is very difficult to see however. You could easily have a detective, spouse, or dry cleaner find these tiny spots on a garment, vehicle seat, or window blinds. If on clothing, consider putting the spatter on something like socks, undershirt, or underwear that would have been covered during the suspect’s version of events (or denial of events). That not only places them at the scene but could also place them in a state of undress at the time of blood loss. You get the picture. Be creative and use your imagination to produce a big plot twist.
