Monthly Archives: August 2011
Digging a Grave: The Criminal Perspective
Training Grave Site
Over the years I’ve dug my fair share of graves (for research of course) and I can tell you one thing unequivocally: it sucks. I suppose there are technically two broad categories of grave digging techniques. The first is mechanical which involves the use of mechanized heavy equipment like a backhoe or bobcat. These types of graves are not as common as you might imagine so I’ll discuss the other category; manual digging. Digging a grave by hand is very labor intensive. Actually, a killer may expend quite a bit of energy just getting the body to the grave site. Hauling a dead body over uneven ground can pose a lot of challenges and risks (stumbling, twisting an ankle, etc). Most of these activities are done at night which increases the risk of injury.
Once at the grave site the real fun begins. One of the biggest factors affecting success is the soil type. Soil is composed of several horizons and the conditions a few feet down may be totally different from ground level. Some areas are simply not good for grave digging because of a high water table or bedrock. I can just imagine the frustration some killer must feel when hitting bedrock 12″ down. Assuming they can dig down to a respectable level like 3-4 feet there are other challenges as well.
Graves typically taper in towards the bottom. It’s difficult to keep the bottom of the grave as wide as the top of the grave. This means that the body won’t fit as well when it’s dumped in even if the opening looks big enough. Part of this relates to the way we dig, the other part is the collapse of dirt from the side walls. This is even more pronounced in sandy soils. So even if you dig three feet down the bottom of your hole may be so small that the body only fits two feet down. Also, if the grave length is too short then the head and or feet may have to be propped up on the ends making them even shallower (think of how a body sits in a bathtub).
An adult sized grave in clay soil can take 2-3 hours to dig (assuming you have a physically fit criminal) and when it’s over the criminal could be exhausted. In this state he’s more likely to make a mistake. One possible mistake is leaving behind something that may link him to the crime. Remember; it’s dark, he’s tired, maybe during the digging he took off a shirt or watch. Maybe he dropped a pocket knife or left the shovel behind. These items may also fall into the grave and get buried with the body without him realizing it.Chances of a mistake are magnified if he is startled by something. Seeing car headlights or hearing a dog barking might make them rush and in turn make a mistake.
One thing about filling the grave is that you can never get all of the dirt back in. This is due to the compaction of undisturbed soil. It has taken thousands of years to compact and by digging it up you introduce all new edges and air pockets. Some criminals may try to stomp the soil down leaving boot impressions which can last for days. In the end there will always be indicators of the grave site if you know what you are looking for.
Filled Grave Site
It’s important to keep these things in mind if you plan on having your character perform such an act. If your bad guy has a bad back or walks with a limp digging a grave is going to be difficult. He’s not going to haul a 200lb man uphill, dig a grave, and then meet up with his new girlfriend to go dancing. Also, because the process takes a long time you shouldn’t have the grave somewhere (like a public park) where someone is going to pass by every thirty minutes. Remember, it doesn’t matter what does happen but rather, what the suspect believes will happen. They generally avoid anywhere there is even a small chance of being discovered.
Crime Scene Photography Circa 1920′s: The Magnesium Powder Flash
Crime scene photography has seen enormous advances in the past century. Heck, even in the past ten years the advent of high quality digital cameras is a quantum leap in technology. When I started out in the field we used 35mm film and developed it ourselves in a real darkroom (not a digital darkroom). I’m pretty clumsy in daylight so putting me in a darkroom with moving parts and chemistry is not such a hot idea. We would shoot hundreds, sometimes thousands of photos just to ensure that we got the scene documented well. We didn’t have a little LCD screen or metadata to review before moving on. I thought I had it rough.
Then I began researching how crime scene investigators of generations past had to do the same tasks. I read about criminalists having to transport their camera equipment by mule and setting up a makeshift darkroom in a tent! Unlike today, they took only a few pictures of a crime scene as it was labor intensive and expensive. A few years back I read a funny account of a criminalist named Ed Tangen who experienced a major problem with a magnesium flash powder tray while photographing a dead body. In order to produce enough light for an indoor photograph photographers of the day used a tray filled with an explosive powder (such as magnesium or lycopodium) which created a flash of light. This method is sometimes referred to as open flash photography (see video below). You will probably recognize the technique from old western movies.
Ed Tangen was trying to photograph the body of a woman found dead in her bathtub in Boulder, Colorado (USA). His equipment was large and bulky and took some time to set up. He ordered all the police out of the room while he readied the exposure. The officers on scene remembered hearing a “pop” followed by a long string of swear words by Tangen. Rushing into the room they found Tangen and the dead woman covered in unburned flash powder that had improperly ignited. The place was a mess to say the least! So today when I hear young criminalists complain about how long they have to wait for a digital image to come up on the scree I think about Ed.
If you are writing a historical murder mystery keep in mind that many of the things CSIs take for granted today were monumental tasks back then. The equipment was difficult to use and stories like the one above are not uncommon. The “malfunctions” and the general challenges associated with old equipment really limited what investigators could accomplish at historical crime scenes. They did a great job with what they had available to them but its hard for modern photographers to comprehend these challenges, especially crime scene photographers.
The First Blow in Bloodstain Pattern Analysis
Dexter fans remember the pilot episode when he strikes the head of the dummy causing blood to spatter all over the crime lab wall. It was a striking scene and is very similar to what real bloodstain pattern analysts do when reconstructing bloodstain patterns. But there is one key difference between these experiments and real life. In real life, the blood is not present before the injury.
Bloodstain pattern analysts have a saying: The first blow starts the flow. In practical terms this means that the first blow will not cause blood to spatter because the blood has not yet flowed out of the wound. Blood has to pool or gather before it can be spattered or transferred. This also means that when you do see spatter there is good reason to believe that at least two blows have been made; at a minimum.
Sometimes a victim will suffer multiple blows in quick succession but other times there is a delay. You can use this in your story, especially if you have an underdog detective or PI who comes in after the fact to discover “key” evidence. There is a natural tendency for investigators to concentrate on the areas with the most evidence (like blood spatter). It’s like a gravitational pull or something. But a really good investigator looks around the periphery as well. Bad guys typically come from outside the crime scene and so it makes sense to look at those areas where they may have entered, exited, and other activity (like getting into a vehicle).
Imagine a crime where the victim is ambushed on their back patio or on the walkway leading up to their home. There may be just a single blood drop in that location from the initial blow. But what if paramedics brought the victim out that way and caused other bloodstains too? What would make the one from the assault different? Maybe it was located at a higher elevation than the gurney the victim was rolled out on. Perhaps the directionality was inconsistent. Anyway, maybe your character finds that odd bloodstain or whatever and starts looking around only to find a key piece of evidence under some plants or in the mulch. Something to think about.
Do CSIs Really Use Chalk Outlines?
This question has come up from some readers so I’m going to address when CSI’s might mark the position of bodies or other evidence. 99% of the time we do not use chalk (or something similar) to trace an outline of a dead body. Actually, I’m not entirely sure if this was ever a common practice or if it was just a product of television and film. I’ve reviewed a lot of historical crime scene photos and I’ve rarely seen any type of marking, let alone a full outline. Before the advent of insta-matic (Polaroid) or digital cameras I can imagine an investigator marking a body position before it was moved so he could keep that “perspective” while investigating the scene.
Chalk Outline
CSIs certainly take measurements to various points of the body (hands, feet, head, elbow, etc) so the body can be properly scaled and drawn into a crime scene sketch. Typically this is all that’s needed. If, however, the CSI plans to remove the carpeting to be used later for a reconstruction or in court then they may decide to mark the location of those measurement points with something like a black sharpie marker. You wouldn’t trace the entire body but you might mark the location of the hands, feet, or head as well as any relevant objects. This can be very helpful if the room contains little or no furniture that can be used as a point of reference in the crime scene photographs.
In such cases, if the position of these items are marked then there is less risk of losing the proper perspective months or years later when re-creating the room for the courts. Defense attorneys will also have a harder time arguing that your reconstruction is not putting the victim back into the proper position. Of course, before we do anything like this around a dead body we would need to consult with the Coroner or Medical Examiner (at least in the United States).
If the body is located outdoors in a publicly accessible location, we may need to move the body before sophisticated measuring devices (like a total station) can be brought in. Unlike an interior room you may not have any fixed point (like a wall) that is close by in a large open field. Under these circumstances the CSI might mark the main body locations with pin flags or other markers that can be mapped in later when the total station can be set up. But these conditions aren’t very common and CSIs take a lot of photographs in most cases. I have used spray paint to mark the locations of vehicle tires at the scene of an accident so that the vehicles could be moved but obviously I would never spray paint a body!
So when describing your crime scene you’d be better off leaving the chalk in the classroom.
Normalcy Bias and the Aftermath of Crime
Trash at a crime scene can be a treasure trove
Normalcy bias is a term that refers to a person’s inability to react properly in times of crisis; instead, acting as if everything is normal. Now I’m no psychologist, and while this condition is primarily related to disasters, it seems to me that criminals can have similar reactions during the events surrounding the commission of a crime. In some ways a crime like murder is a kind of disaster in that actions are dramatic, adrenalin is ramped up, and things rarely go as planned. Most murderers don’t have a lot of personal experience with killing to draw upon and the emotions and reactions they experience may be very foreign to them to say the least. Their brain has a hard time processing this new data and they revert to common behaviors as their brain attempts to operate in this chaos.
Some may call it a lack of focus, others may refer to it as tunnel vision, but that is only one part of the phenomenon. I think the bigger part is conditioning. Allow me to provide an example. It is not uncommon for a rapist to throw a condom away in the bathroom trash can after a rape. I remember seeing that for the first time and being blown away. Why? Why leave something so incriminating right on top for the police to find? Of course, one possibility is that the rapist didn’t believe he committed a rape and therefore had nothing to hide. But that can’t account for all of the occurrences. Additionally, criminals tend to throw away other kinds of incriminating evidence such as weapons, clothing, documents, etc in readily accessible trash cans as well.
Condom found in trash can
I once saw a case where a man committed a rape homicide and while walking away from the crime scene left key evidence linking him to the crime in a dumpster in the alley behind the victim’s home. Did he really not think the police would search there? It’s not like he drove it into another jurisdiction or made any attempt to destroy it. Hell, he didn’t even try to hide it under other trash. So why would a criminal act in such a manner?
Again, not being a psychologist I can’t say what goes through every criminal’s mind but it seems to me that people are conditioned to perform certain acts with regularity (like discarding unwanted objects in a trash can) and in times of stress our consciousness engages in a kind of auto-pilot mode where we perform these acts without consideration. Undoubtedly, the criminal is not thinking about what might become of the evidence. The unwanted items are in the trash, never to be seen by him again, or so he thinks.
In some ways I think it’s like the routines we perform day in and day out. The route we take to work, the websites we open in a particular order, where we go to lunch. All of these things can become so repetitive that they seem to happen as part of a pre-ordained plan. So why should criminals act any differently?
Now in a novel it makes for a much better story to have a savvy criminal. I guess the point I’m trying to make is that even criminals can behave in ways that defy common sense and while engaging in these “normal” activities they may leave behind clues for your even savvier protagonist. Maybe they have to go outside for a smoke and then simply drop it on the ground. Maybe they have to go to their neighborhood bar for a drink and wash-up their bloody hands in the bathroom. There are a lot of possibilities to consider using but throwing incriminating evidence in the trash is one of the most common I have seen.
How To Spot A Counterfeit Bill
Two things are working in favor for the modern small time counterfeiter; technology and ubiquity. With affordable high quality scanners and printers a garden variety crook can reproduce passable counterfeit bills in most global currencies. Because of this a number of governments have stepped up their anti-counterfeiting measures by adding a variety of features difficult, if not impossible, to replicate. Modern movies tend to portray counterfeiters as members of well financed multinational criminal organizations with nearly fool-proof counterfeiting techniques. I have no doubt they exist, but what about the lowly street hoodlum trying to pass off a small bill?
This is where the issue of ubiquity comes in. The simple fact is that most people don’t carefully inspect their money. You might pick up a number of bills from the drive-thru window and, aside from arranging them in numerical order, you stuff them in your purse or wallet until you need them again right? I mean, how many of us actually examine a bill? Now imagine you’re a clerk at the grocery store or gas station exchanging bill all day long. You can start to imagine how simple it is for someone to make that initial pass.
A number of high-tech countermeasures found in bills require specialized equipment like an alternate light source or microscope to detect but there are some things that your street-wise detective or PI can look for to detect phony bills as well. First is the paper. Take a bill our of your wallet, close your eyes, and feel the paper. How would you describe it? Now take some typical bond paper (from your printer) and feel that. How does it differ? Aside from touch there is also the appearance of the counterfeit bill.
Close-up detail on a $20.00 bill
Same area on a counterfeit bill. Notice the "fuzzy" out of focus detail
Color is one aspect of course but bills can and do fade so it doesn’t have to be exact to pass a casual inspection. Another aspect is the quality of the printing. Look at the detail in the magnified image below of a real US bill. Most retail printers won’t be able to print at that level of detail and the intricacy of the webbing will be lost. This can easily be seen with a magnifying glass. Borders are another giveaway. After printing the paper has to be cut and no matter how good the printing job is, if the edges aren’t straight then you probably have a counterfeit bill. Crooks don’t often think about this part but carefully looking at the border for changes in width is another simple way to spot a forgery.
Uneven edges on a counterfeit $20.00 bill with backlighting
Lastly, there is an inexpensive and simple tool that many banks and retailers can use to spot a phony bill and that is a counterfeit detection pen. It looks like an everyday yellow highlighter and works with most Western currencies except Canadian. Simply make a mark on the bill in question. If the ink turns brown or black the bill is counterfeit. Easy Peasy!
Brown marking from counterfeit detection pen
If police can find the suspect’s home or office where the counterfeiting is taking place they can usually find the computer, printer, and software they have been using. There may also be test runs of bills in the trash that weren’t good enough to use. Also, if your bad guy is counterfeiting money there is a very good chance they are making false ID’s, food stamps, checks, etc. A good businessman stays diversified right?
Estimating the Time of Death: Rigor Mortis
Body in full Rigor Mortis
Rigor Mortis, like Livor Mortis or vitreous fluid, is a post-mortem change in the body that may allow investigators to establish an approximate time since death. A few hours after a person dies (and the circulatory system has stopped) the joints of the body begin to stiffen. As they stiffen they become locked into whatever position they were at the time of death (dead bodies aren’t supposed to move right?). The process is affected by temperature but as a rule of thumb for an indoor crime scene the process is noticeable after about three hours and reaches its maximum “stiffness” after about 12 hours. At this point it is very difficult to straighten the limbs and it seems as if you’d need a sledgehammer to bend them in another direction. The joint stiffness will slowly dissipate from this point leaving the body completely after about 72 hours.
One downside to the process is getting the body to fit into a standard body bag. Aside from providing another condition to estimate an approximate time since death, Rigor Mortis is also helpful in understanding the victim’s body position for crime scene reconstruction. Most people choose to avoid dead bodies unless it’s their job. So aside from first responders and the medical examiner why would someone else move a body? Of course, there is always the possibility that a family member or friend who discovers the body may try to administer some form of first aid but that isn’t too common with bodies in Rigor. Another possibility is an unscrupulous passer-by when your victim is found outdoors. Not to stereotype, but imagine a homeless person or drug addict finding the corpse of a well dressed businessman laying in the bushes of a field or something. It wouldn’t be that big a stretch for them to roll the guy and go through his pockets would it?
The last and perhaps the best possibility for your novel is having the killer come back. Returning to the scene of the crime is a high risk move but it happens. Murders are a messy and chaotic act in which your bad guy will likely be rushed. Fast forward several hours and the killer will likely be going out of his mind reliving the events (unless he’s a sociopath of course). As the killer plays the events over and over in their head they start to second guess themselves. Did I leave anything there? Will the cops believe she really shot herself? Stuff like that. For some killers the stress is unbearable and they make a decision to return and do damage control.
This is great news for CSIs and for authors because any action they take leaves more evidence for us to consider. Let’s say a victim was hit over the head with a frying pan while they laid in bed and died. Then, six hours later, the killer returns and decides that they want to stage the crime scene to look like the victim fell down the stairs and hit their head. Sounds reasonable to a dirtbag right? But when they pull the body from the bed and toss her down the stairs her body is going to be outstretched and inconsistent with what we would expect to find in an accident. Not to mention all the other evidence they will likely create in the staging process.
As an author you might consider the body position to be a key clue to discovering the place where the victim was killed. For example, maybe your victim is in a sitting position but reclined at an extreme angle. That may match the reclined driver’s seat of a car discovered in another part of town. In such a case the killer may have returned to separate the body from the car because they felt there was something about the two that would point towards the killer’s identity. There are a lot of possibilities at your fingertips so role play a bit and have some fun with it!
Clues From Indented Writing
As the prevalence of electronic communications increases the hand-written note or letter is becoming less common at crime scenes. They are still very important though. People take notes for all kinds of things. Groceries, phone numbers, addresses, and bank hold-up notes to name a few. But can the police find any useful evidence if the note is taken away and destroyed? The answer is a resounding YES! If the note was written on a pad of paper or if some kind of paper or cardboard was below the note as it was written then the CSI may be able to detect indented writing. Indented writing is created by the force of the pen or pencil compressing the paper below the sheet being written on.
Page With Indented Writing From Suspect Residence
You can try this experiment at home. Take a pad of paper and write something on the top sheet with a ball point pen. Tear off the top sheet and take the pad into a darkened room (like a windowless bathroom) along with a flashlight. Turn off all the lights except the flashlight and lay the pad on the counter. Then hold the light at an oblique angle and voila! You will see the message from the page that had been removed.
Preparing a document for toner application with an ESDA
When CSIs search a suspect’s home or vehicle they don’t see a blank sheet of paper and think “oh well, nothing there I guess”; they see a challenge. They want to process that sheet for a number of things included indented writing. The oblique lighting technique is the simplest field technique to use. Back in the laboratory we can further enhance indented writing through the use of an Electrostatic Detection Apparatus (ESDA). These devices (about the size of a desk top printer uses an electrostatic charges (similar to a shoe print lifter) on the paper and charge sensitive toners to enhance the microscopic damage caused to the paper through handwriting. These devices are so sensitive that an analyst may be able to detect messages several sheets below the original note.
Applying toner to the prepared document
Consider using this type of evidence in your storyline. The fact that indented writing is not easily seen means your character might have to do some digging to find it. The clue could be as simple as a phone number on a post-it note thrown in the trash to writing from a page torn out of a teenage girl’s diary. The options are endless so let your imagination run wild with the possibilities.
Handwriting sample developed with the ESDA
A special thanks to the folks at Foster & Freeman for permission to use the images of the ESDA!
Innocuous Evidence: The CSI Curse
Are the Missing Knives Relevant?
Crime scenes can occur just about anywhere but most often they happen in places with a lot of human activity not related to the crime. Take your average residence or even a convenience store. Stuff is happening there all day every day right? All of those activities leave behind “evidence” just as criminal activity does. The only difference is that CSIs don’t generally care if so-and-so threw a candy wrapper on the floor, brewed a pot of coffee, or left their newspaper spread out all over the table because none of these activities are a crime.
I often tell young criminalists that CSIs are not “garbage collectors”. Simply put, we can’t collect everything from a crime scene. You have to use your training and experience as a filter to take items which actually support or refute the legal elements of the crime. Aside from the physical requirements needed to house all these items you also have to make sense of them. This is where theory collides with reality and hinges upon the fact that as criminalists we can not know the complete history of any location (all activities that occurred there). Exhibit A: innocuous evidence.
Innocuous evidence are items that have significance to an individual but do not possess any quality making them suspicious to the average detective. It might be an item of jewelry left on the night stand, a coffee mug on the kitchen counter, or a baseball cap on a chair. CSIs easily recognize the significance of things like fired cartridge cases, bloodstains, or drugs. These items are commonly encountered and generally yield probative information about a crime. They are what I call Tier1 artifacts.
Are Any of These Items Significant to the Crime?
But as I noted above, crimes often occur in centers of non-criminal human activity so deciding what items (or conditions) relate to the crime and what items (or conditions) are simply the result of human occupation can be tricky. There is a great scene in the movie Seven with Brad Pitt that illustrates this point. In the movie, the widow of a recent homicide victim is asked to look at photographs of the crime scene to see if anything looks out-of-place. After studying the photos she notices that an abstract photo on the office wall is hung upside down. You’d never notice that unless you were intimately familiar with the canvass and its normal orientation.
This is great news for authors because it provides a lot of opportunities to inject significant items or conditions that may go unnoticed at first but then serve to blow the case wide open later on in the story. Select something that blends into the crime scene environment and wouldn’t seem suspicious to the detective or CSI. It might be something in the victim’s purse or vehicle that is tangential to the crime scene. It could be a receipt to a place the victim would never go for some reason but the average person would. Only someone who really knew the victim would recognize that. Following up on the lead maybe your character gets a copy of the surveillance tape showing the victim and the suspect. However you use it, innocuous items are common place at crime scenes. 99% of the time they aren’t related to the crime but once in a while they may break a case wide open.
Can You Really Evade a Bloodhound by Crossing a River?
Bloodhound and Handler Working a Scent
The tracking prowess of Bloodhounds has been a staple of crime literature since 1890 when Sir Arthur Conan Doyle introduced “Toby” in The Sign of the Four. In fact, from Doyle’s descriptions some might argue that the breed possesses almost magical ability to follow a scent trail. Well, if you define having over 4 billion olfactory receptor cells as being “magical” then I guess I’d agree. You see, the human body is constantly shedding millions of dead skin cells as we move around. These cells contain a unique scent that the dog can identify us by. It’s as if we are dropping radio isotopes and the bloodhound is a Geiger counter. Their over sized floppy ears and never ending supply of saliva maximize their ability to stir up and capture the cells from the ground as they track nose down to the ground.
Bloodhounds have been bred to track and I have watched them find evidence when no other breed could. Over my career I’ve had the good fortune to work with several outstanding dogs and handlers who have literally tracked criminals to their front door step. They have tracked moving vehicles for dozens of miles, found bodies under water, and even grave sites in flood ravaged areas. A well-trained dog and handler and an invaluable asset to a law enforcement agency.
But if you watch enough television you might think that this amazing animal has an Achille’s heel. If you’re a bad guy being chased by bloodhounds all you have to do is cross a river and you’re home free right? Wrong. I’m not sure how this idea came to be so common. Perhaps as authors we simply can’t fathom a Superman without a Kryptonite. Every great character has to have some fallibility otherwise they seem too good to be true right? Whatever the reason, the idea that crossing a river ends the chase is simply not true.
In the movies it’s always a small river too; never the Mississippi. Imagine a group of rough and tough lawmen chasing a murderer when to their shock and horror the trail ends at a small river bank. ”Weeeeell shucks! That son-of-a-gun crossed through this knee deep water! He’s gone for sure now. Let’s call it a night and head to Dunkin’ Donuts”. God help us all if law enforcement ever gets to that point.
The fact of the matter is that bloodhounds can track a scent over water. It’s true that the moving water will carry a scent down-stream but this is only an issue if the bad guy is moving upstream (away from the scent). Coupled with that is the fact that even if a bad guy wanted to travel through a river there are several things that work to his or her disadvantage. As any fly fisherman will attest; walking along a stream bed is tricky. The rocky bottom is uneven and slippery; and then there’s the current. In places like Colorado the water can be just above freezing even in the Summer at some elevations! The fact of the matter is that you slow your speed of escape tremendously in water and this is not what the bad guy wants. Sooner or later they have to get out and onto dry land again.
Bloodhound in a Boat on a Lake Search
This is why a good bloodhound handler simply works the banks. In all likelihood the suspect will leave signs of disturbance like shoe impressions or damaged vegetation that even a rookie could find. If by some chance he gets out on some rocks the bad guy is still shedding skin cells and a well-trained bloodhound will quickly recover the scent. In a way, I suppose we should encourage all criminals to wade into rivers if for no other reason than to slow down their escape. But if you’re planning on using this scenario in a novel just be aware that it doesn’t work well unless you’re cops are jonesin for a doughnut fix!
