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ENTOMOLOGY AND THE ROLL IT PLAYS

Entomology PART ONE 

(P2 will discuss how entomology is used in death investigations)

When a body dies, human or animal, it begins to decompose.  In the beginning it can be very difficult to see any signs of decomposition.  Of course, just as with other situations, the scene (inside or outside, temperature, etc) play a very big factor in how quickly decomposition begins to happen. However, insects and animals have such a hyper sense of smell, they seem to know within minutes.  Flies show up very quickly and are usually the first to arrive.  Obviously, if a person dies in a clean house, with no open windows or doors where flies have access to enter, then the flies are delayed.  If there is someone else in the house and the authorities are notified quickly, then it is unlikely flies will have access to the body.

In a different scenario, such as a house in which the person is alone, and has an open window which does not have a screen, or an open slider without a screen, then flies have quick and easy access.  In a short amount of time, flies will enter and explore the body.  If the body is dressed or perhaps covered in bed where mostly the neck and face are the only areas easily accessible. If the body is uninjured, then the flies will go to the eyes, nose and mouth and occasionally the ears.  They will find a warm, moist place and lay their eggs.

If the body is inside, completely naked and the flies have access to come inside they will go for they usual eyes, nose and mouth, but they will also go for any other warm moist areas they can access.  If the house is in bad shape, such as a hoarder house, there will also be ants, cockroaches and rodents already in the house which will also investigate the body but will be interested in it as a food source more than to lay eggs.  Ants often leave tracks of little bite marks which can often be wrongly thought to be abrasions or scratches. Because the person is dead when the ants bite, there is no swelling or inflammatory response.

If the body is outside, then the flies and other local insects will come right away.  The hotter the temperature the faster the eggs laid by the flies will mature.  If there are any wounds, the flies will concentrate there as well as the usual places I mentioned previously.

There are so many variables when using forensic entomology to make determinations in the investigation.  It is very important to photograph the body with the insects in place before collecting specimens.  Then carefully log them as you collect.  One area at a time, collect live specimens as well as  specimens to be preserved at their current stage. Log and photograph as you go as well as labeling each collection container.

In order to better understand the daily growth patterns, I grew maggots in my yard with a controlled environment. I photographed and documented daily.  I used animal liver that I obtained from the market and did not disrespect any persons in order to carry out my experiment.

The following photos are from my experiments from growing fly maggots at my residence.

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You can see flies on the fresh specimen as they lay eggs.

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Eggs in their early stage. Can usually be seen in 24 hours or so. They are usually laid in a mass, as you can see in the lower right of the photo.

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This is a piece of the liver after the maggots have been feeding off of it.  You can see it is desiccated or dried out.

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Through the photos you can see the maggots changing as they grow. When they are ready to change they crawl under something or into the dirt and their outer layer becomes a hardened shell.  This is called the Pupa stage.

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The flies emerge in about 2 weeks depending on the weather and conditions of their surroundings. In the photo above you can see a green bottle fly and a gold bottle fly that emerged from the casings.

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Some of the tools I keep in my collection kit.

In part 2, I will discuss how entomology can be used in death investigations.

 

Decomposition

DECOMPOSITION is the process of the body breaking down and decaying. This starts as soon as death occurs however it is not immediately visible. There are many factors in decomposition and the rate at which is occurs.  The location of the body is one main factor – is it inside or outside.  The temperature of the location is another big factor.  The hotter the location the faster the body will decompose.  The condition of the body is another factor. Whether the body muscular or obese will be a factor as fat will decompose at a different rate than muscle.   If the person/body is sick or damaged in some way in which air, moisture or insects (covered in the next post) will reach the organs faster than normal, can speed up the process.

This are screen shots from my teaching powerpoint,  It shows some of the variations of decomposition.

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The majority of these photos were taken of decomposed bodies inside residences.  The one with the foot labeled “desiccation”  was of a body that had been inside a warm residence for at least 2 months before being found and was essentially closer to being mummified.  This is what you would normally see of remains left outside in the heat for a long period of time.

The Mortis Brothers. Who??? (What!)

The Mortis Brothers  

Rigor Mortis, Algor Mortis and Livor Mortis – sometimes referred to as the “Mortis Brothers”

Rigor Mortis

Rigor Mortis is due to a biochemical change in the muscles that occurs several hours after death, though the time of its onset after death depends on the ambient temperature.

  • Within ½ to 1 hour = becomes apparent

  • Approx 12 hours = increases to max

  • Approx 12 hours = set / stays

  • Approx 12 hours = decreases / relaxes

  • Once fully established, the breaking of rigor in joints is irreversible and it will not reappear.

  • Rigor mortis appearance and disappearance is accelerated by prior exercise, convulsions, electrocution or hot environmental temperature. In a hot environment, for example, the rigor mortis may disappear in only nine to twelve hours.

Algor Mortis

Under average conditions, the body cools at a rate of 2.0 F to 2.5 F per hour during the first hours, and slower thereafter, with an average loss of 1.5 F to 2 F during the first twelve hours, and 1 F for the next twelve to eighteen hours.

Livor Mortis aka Lividity

  • Postmortem Lividity or postmortem hypostasis is a purplish-blue discoloration due to the settling of blood by gravitational forces within dilated, toneless capillaries of the deceased’s skin.

  • Blood loss and/or anemia can cause difficulty in discerning Lividity.

  • In individuals with dark skin pigmentation, Lividity in the skin can go unnoticed.

  • In early stages, livor can be blanched by compression.

  • In certain cases, it may be difficult to distinguish between postmortem livor and ante mortem bruises. Incision of the skin may be required.

There are many factors that affect rigor mortis, so the times listed above are only averaged guidelines.  Whether a person is obese or thin and muscular play a big factor since rigor occurs in the muscles, and certain disease processes can alter the time as well.  We use stages of rigor to help determine if the story we are told, as well as the scene, fits with the way we find rigor to be. For example, if we are told someone was speaking just before death, but they are stiff with rigor, we know the story is not accurate.  Another example would be if the rigor was not consistent with the position the person is now observed. We cannot pin point a time of death from rigor mortis. We can only determine if it is consistent with the time frame and story we are told.

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Algor Mortis

Under average conditions, the body cools at a rate of 2.0 F to 2.5 F per hour during the first hours, and slower thereafter, with an average loss of 1.5 F to 2 F during the first twelve hours, and 1 F for the next twelve to eighteen hours. As with rigor mortis, algor mortis times are a guideline and not exact.  A person’s condition (such as body fat or disease) can play a part in how quickly – or slowly – their temperature drops. If they are on a pillow top mattress they will stay warmer longer because the pillow top retains body heat.  If they are inside but near an open window and with cold air blowing in, they will cool down faster. If we know someone has been deceased for awhile – such as several hours – but they are outside and their temperature is still very high, and especially if it is higher than normal, then we must consider heat exposure as a factor in their death. This can occur inside too, when someone does not have adequate temperature regulation and it is very hot outside. If it is very cold, and the decedent is inadequately dressed or outside, then we use their temperature to help determine if exposure to the cold could be a factor in their death.

Livor Mortis or Lividity.

Postmortem Lividity or postmortem hypostasis is a purplish-blue discoloration due to the settling of blood by gravitational forces within dilated, toneless capillaries of the deceased’s skin.

Blood loss and/or anemia can cause difficulty in discerning Lividity.  In individuals with dark skin pigmentation, Lividity in the skin can go unnoticed.  In early stages, livor can be blanched by compression.  In certain cases, it may be difficult to distinguish between postmortem livor and ante mortem bruises.  Incision of the skin may be required.

Lividity is often mistaken for bruising by the untrained. One of the ways we check lividity, is by applying moderate pressure with a finger.  If the pressure is able to change the color to white, we consider that “blanching” and lividity is NOT set.  If the coloring does not change, then we consider the lividity “set” or “fixed.” (see pic)

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Occasionally we will see some lividity on both the anterior (front) and posterior (back) of the body.  This indicates the body had been in a position for awhile, then moved to another position. If we are told the decedent was NOT moved, then our findings contradict the story. This is important, however it is not unusual for someone to find their loved one face down and roll them over when they don’t respond. If they admit this up front, then mixed lividity would not be as surprising.  Lividity can often tell us where the person had been laying. See the photo inserted.  You can see where the decedent had been lying on a flat service causing part of their back to not have lividity.

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In an investigation, we use each finding as part of the puzzle of what happened.  By checking many different factors, we can discover if there is something that does not fit with the story and/or the other findings. This helps us determine if there is something suspicious in what might otherwise appear to be a nature or non-criminal death.

 

Time of death

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TIME OF DEATH (TOD)

Establishing time of death is often more complicated than they make it seem on television.  The following information is based on California laws regarding death certificate criteria.

Determining TOD in an unwitnessed death is almost impossible to do.  There are times when someone dies alone or “unwitnessed” and there is something that can help us narrow down the approximate time the person died, such as a gunshot being heard, or the dying person being on the phone with someone when they stop breathing, or an event that caused an immediately fatal injury such as a traffic accident, explosion, a lightning strike and other similar events.  For example, there was a case handled by my office in which someone was attempting to steal copper wiring from a metal control box. When they attempted to cut the wire, they were electrocuted and actually caught fire. Although the event was not witnessed, there was a loss of power to a small area and the time of the power loss was recorded by the company as well as the people who lost power.  In that instance we can have a pretty good idea what time death occurred because it would have been instantaneous due to the amount of electricity.  There have also been many time a traffic accident is heard, and when first responders arrive one or more of the victims are already deceased and their injury is one that would be immediately fatal such as extreme crushing injuries to the head and chest. One issue with time of death is the person has to be officially pronounced dead by someone qualified to do so. This is usually a first responder such as a paramedic, or law enforcement official. In hospital deaths, it is usually a physician, or a nurse at the direction of a physician.  In many cases, the time of death (TOD) is the pronouncement time as recorded by the physician or first responder.

However, in unwitnessed cases, we often use the term FOUND TIME instead of TIME OF DEATH.  The reason for this is we do not know the actual time of death.  We take the time the first responder arrived and confirmed the person was deceased. We then determine when the decedent was last known to be alive.  If it was not on the same day they were found, we will list a FOUND DATE, then list the pronouncement time listed in the TOD space. This basically certifies we cannot establish the exact time of death but only when the person was found.  In our investigative report we will elaborate more about the last time known alive, and how long the physical findings indicate the person was probably deceased.  This is where temperatures, exposure, stages of rigor mortis and decomposition come into play.  I will discuss those topics in a later post….

A second area on the death certificate which is important in NON-NATURAL deaths, is the INJURY section. In some cases, the injury date and time is the same or very near the time of death, and in others it can be years apart. In an unwitnessed death this entry is often marked UNKNOWN. If a gunshot, traffic accident or other factor can provide the injury time we will use it.

Grief…. Is “Closure” possible??

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CLOSURE….. I have come to dislike that word.  So many people use it.  You hear cops, doctors, family and television use that word. The family needs closure. I want closure.  If I just know who did it, or what happened, or if we just find the body, or if the suspect gets convicted…. THEN I/we/they will have closure. NO I say they won’t. Let me explain WHY I say this. To say someone will have closure at some point after the loss of a loved one indicates that the living will be able to say I got my answer and now I am done grieving and will move on. As someone who has lost many friends and family, including both of my parents, I don’t believe there is any answer a loved one can receive that will bring THAT much relief. I also, at least for myself, do not believe someone ever stops grieving.  We may reach a point in which we stop allowing our grief to control our life. We may reach a point where we are now able to get up, go out into the world and move forward but that does not mean we are done grieving.  My mother has been gone for over 10 years now, but I still miss her, and some days I truly grieve for her – and yet I am finally at a place I can go through boxes I packed up after she died, see memories, see things written in her handwriting, and once in rare instance come across an article of clothing that has been packed away in such form that I can still smell my mom’s perfume or more often her cigarettes, and it makes me smile sadly at the memory it invokes, but I no longer curl up in a fetal position and cry.

It is my personal and professional opinion that there is no set time for grieving. Is it possible to be locked in your grief to the point of it being unhealthy – of course, but I hate when someone tells a grieving person that it has been long enough and the need to “get over it”. Please do not criticize, or judge a person who is grieving. Do not ask them what will give them closure, because I believe there is no true “thing” for anyone that completely provides closure.

Grieving to little is just as bad. I say this because if you just shove those feelings deep into the back of your mind and force yourself to move on and not think about then someday, one day, I assure you – you will crack and shatter, and it will not be pretty.

When I would speak with families during the process of my investigations, I would tell them to take their time and do not be hard on themselves or on each other. Everyone grieves differently.  If you have lost more than one loved one, you will likely grieve differently with each. It also matters how you find out about the loss of your loved one.  For those of us (yes including me) have been the one to find your loved one dead from a traumatic event, such as suicide, homicide, decomposed, etc., it is even more traumatizing than being at the bedside in a hospital or being told after the fact. Once you see your loved one like that, you cannot flush the vision out of your mind. Eventually you can go days, weeks, maybe even months without thinking about it, but it will come and go and it will never go away completely.  I would always discourage and sometimes prevent family members who would come to the scene from seeing their loved one in a bad way. Working a job like mine made my grief harder to push past.

In closing I beg of you to please be supportive to those who grieve and if/when you (the reader) are grieving, please seek a support group or someone you trust if you need to talk about it.  Don’t keep it all inside and wait until you explode.  Do something that helps you. One thing I did was make a memorial garden for my parents. My husband made a beautiful wooden bench and I can sit and “visit” my parents anytime as they both have engraved granite urns that have been placed in the garden. My cousin had a star named after my mom.  There are little things you can do to honor and memorialize your loved ones.

The Autopsy

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AN EXTENSIVE ACCOUNT OF AUTOPSIES

Any case in which additional information is needed from examining the organs or closer inspection of injuries will necessitate an autopsy.  This process is also often referred to as a “post-mortem examination.”  In most cases, autopsies are performed by pathologists assisted by technicians. Each county varies slightly, depending on whether they are a Medical Examiner’s office or part of the Coroner system. The main difference is political in which the position of Coroner is an elected position and often co-joined with the county Sheriff’s department. That is the type of system I worked in and my experience is based in. Autopsies are done in what is commonly referred to as an autopsy suite. The room is outfitted with special workstations where the table/gurney can be rolled up to the sink area and locked into place with the end of the table resting over the sink.  On either side of the sink are areas for the doctor to perform dissection and study of the organs. There is a scale that hangs over the sink for weighing of organs. Collection containers for body fluids and organ specimens are prepared and labeled prior to the start of the autopsy After the external examination has been completed and blood samples collected, the body is laid supine (flat on back) on the table. The head of the table is able to be raised if needed. The foot end of the table has a hole so the body fluids can drain down special channels in the outer edge of the table and out the hole into a large sink. A special block is placed under the decedent’s neck to raise the head for easier access to the skull and throat. Often, an additional block is placed under the shoulders to allow for easier Y incision.

The hair is parted across the top of the head, from ear to ear. The scalp is opened to the skull with a scalpel (within the ear to ear hairline part). The scalp is then manipulated and separated from the skull and folded down onto the face, and the back down over the back of the skull.  When the skull is exposed, a Stryker saw is used to make a separation in the skull across the front, about the top of the forehead, and another cut is made towards the bottom, across the back of the head.  The 2 cuts are made to intersect, usually about behind the ear area so the “skull cap” can be lifted off and a large opening allows access to the brain. When fully developed, the membranes coving the brain create a tight suction of the cap to the brain.  This suction is usually broken with the use of a “skull key” which has a flat edged protrusion that looks much like a large standard screw driver.  This is gently worked into the top cut and twisted just enough to break the suction. The membranes are removed from the inside of the skull cap to allow the pathologist to examine the inside for evidence of recent or past injury, including staining from brain injuries. The brain is gently separated from the skull sides by running a finger between the brain and the sides. Next, the top of the brain is manipulated to allow visualization of the brain stem. The brain stem is severed as deeply as possible with a scalpel, and the brain and stem are removed and weighed. The cleaned skull cap and remaining skull are examined thoroughly to look for indications of head injuries.  Any fractures or staining (from bleeding in the head) are photographed and noted in detail by the pathologist.

Next a Y incision is made with a scalpel.  The top of the Y starts at each shoulder and meets mid chest over the sternum.  A single incision is then continued from the intersection over the sternum and down the torso, making a small departure around the navel and down to the pelvis. The tissue is then peeled back away from the ribs, and the incision is opened over the abdomen and through the Parietal Peritoneum, exposing the internal organs. Throughout each step the newly exposed area is inspected for trauma or other abnormalities. Pruning shears (or a similar tool) are then used to cut the sternum away from the ribs by cutting the connective tissue (costal cartilage) that holds the sternum to the ribs. The sternum plate is then removed and set aside.  The organs in the chest and abdomen can now be removed.  Some pathologists and technicians prefer to remove them in “blocks” which are several organs removed together and others prefer to remove the organs one at a time.  As each organ is removed, it is weighed, then inspected by the pathologist who looks for injuries, as well as other anomalies such as tumors, scar tissue or congenital defects. As each organ is dissected, a small piece is placed into a “stock” jar to be stored for a determined amount of time, depending on the final cause of death.  For example, natural death stock jars are usually kept for a year, traumatic deaths (suicide, traffic, accident, etc) are kept for 2-3 years and homicides are usually kept for an extended amount of time.

The empty chest and abdominal cavities are closely inspected for injury or anomalies. The bladder, reproductive organs, aorta, esophagus, trachea and bronchial tubes, epiglottis and tongue are removed. Again, these sections of tissue as well as the area they are removed from are examined for injury and anomalies.

When the intestines are removed, the connecting tissue is cut in order to be able to extend the intestines to their length.  The intestines are then cut at the upper end, and the cut continues all the way to the end (rectum). This process is usually referred to as running the bowels. They are then rinsed clean and inspected by the pathologist.

In addition to the blood and vitreous samples taken at the beginning of autopsy, the contents of the stomach, urine, a liver sample and brain sample are collected during the autopsy.

When the internal and external examinations have been completed, the remaining organ and tissue is placed back into the body cavity inside a plastic bag before the remains are sewn closed and wrapped in plastic for transport to a mortuary.

The topics of TOXICOLOGY, INJURIES and CAUSE OF DEATH / MANNER OF DEATH will be covered in separate posts.