Blog Archives
The Autopsy Part 2: The Internal Exam
There has been a lot of interest in how autopsies are performed. Frankly, it’s not something most people experience (in life that is). So I thought it would be informative to give you a little peak behind the curtain and find out how these procedures take place. Consider this a brief summary as each case may require special procedures depending on the crime or suspected cause of death. I have already explained the external examination. Now it is time to discuss the next phase, the internal examination. You might think that all autopsies include an internal examination but in my experience the final call is made by the coroner or medical examiner. Personally, I think every suspicious death autopsy should include an internal exam and most do but, occasionally the coroner may issue a death certificate based solely on the external examination. This may include cases of motor vehicle accidents, suicide, or natural deaths such as a patient dying after a long documented battle with a terminal disease.
The purpose of the internal examination is to fully explore all potential causes of death. Forensic pathologists are concerned with more than just criminal acts resulting in death. They also have an interest in public health and personal medical conditions that may affect the victim’s family members (like a hereditary disease). Likewise, a patient suffering from a terminal disease may die prematurely from improper care or negligence and sometimes the internal examination is the only way to uncover that evidence.
The internal examination begins with what we refer to as the “Y” incision. This is a dissection technique to gain access to the internal organs of the torso. Incisions are made from each shoulder to the sternum and then straight down to the groin. The skin is then reflected (cut) back and the ribs are cut along the sides and the “plate” is then removed to expose the organ area. Each organ is removed, weighed, photographed, and dissected by the pathologist. Small portions of each organ will be preserved for future study and tissue samples will also be collected for histological examination. They are looking for injuries, evidence of disease, as well as the general health of the organ. Pathologists will examine and collect the stomach contents which may reveal last meal evidence or prescription drugs (in cases of drug overdose). All along the way they will be documenting their findings in notes, charts, photographs, and occasionally video.
Then they open the cranium. The pathologist begins by cutting the scalp around the back of the head and then reflecting (peeling) the scalp up over the head to the top of the eyes and on the back side down to the bottom of the skull. This exposes a majority of the cranium. A bone saw is then used to cut through the bone and pull the skull cap off exposing the brain. The bone saw can generate some bone dust and an interesting musty smell so I generally make sure I’m on the other side of the room. The brain is covered in a thin white sheet or film called the dura that resembles an opaque saran wrap (bad analogy but appropriate for non-scientists) that has to be removed before you can access the brain. Once the dura is removed, the brain is removed and examined like the other organs. It may even be sectioned (cut into thin slices) to look for certain pathologies. The pathologist will also be looking for fractures or bruising to the cranium and scalp (as might be found in blunt force trauma). Following the examination of the brain the pathologist will examine the throat. Depending on the circumstances surrounding the death they may be looking for anything from an obstruction (choking) to soot (fire). Of course the mouth will be examined for injury as well. This could include missing teeth, bleeding, bruising, etc.
Black soot in victim’s airway
As I’ve mentioned, each autopsy may require examination and procedures not mentioned here. The order of the examinations (Trunk, head, throat, etc.) may also vary from pathologist to pathologist and the circumstances of the death. Most autopsies are completed in under two hours. Some can take a bit longer if there is extensive trauma to document (like 37 stab wounds). Although the physical procedure is relatively short it may take days or weeks to get all of the toxicology and histology results back (even if done in house) because of backlog. If the victim has evidence of prior injury (like healing fractures, bruising, or evidence of prior surgery) the pathologist will document it and assess if it played a role (contributed) to death. Every medical examiner has different rules as to who may attend the autopsy in person. Some are extremely restrictive (only the pathology staff and one member from the crime lab) others seem to allow anyone to attend. I’ve been in some with a dozen or more people crowding around and that can cause it’s own challenges. As far as evidence retention, the pathologist will take custody of all biological evidence. If there were something inside the body like a bullet, knife tip, or other trace evidence, the crime lab would typically take custody of it.
Today pathologists must physically dissect the body but there may come a day when much of this work is done in what some call a virtual autopsy. You’ll probably never get away from physical sampling but fifty years from now the autopsy procedure may look very different. Watch the below video for a hint at how these procedures may develop. I think if nothing else, the virtual autopsy may be a preferable method for presenting images in court.
As writers you may not want to get too deep into the weeds on autopsy procedure but, it is helpful to understand it. Autopsies are hard for some folks to deal with and some investigators and DAs would prefer not to be there. It’s easy to understand why. It is one thing to see a dead body. It is something else entirely to see one subjected to this procedure. Pathologists exhibit an enormous amount of care when performing these procedures. There is a decorum of professionalism and they don’t tolerate clowning around. It is a very serious event. Having said that it is also a place where emotions can rage inside each individual. Your characters may ride a wave from sorrow to anger and back again before the procedure is completed. Think about how each character might react to the details as they emerge during this procedure and use that to give the reader a little insight to their thought process.
Crime Scene Response: The Call Out
This will be the first in a series of posts on how CSIs respond to and investigate crime scenes. I hope that these posts will give you a little insight to the process which may help you in developing scenes and dialog in your novel. I’ll be speaking exclusively about CSIs who are on-call as opposed to those working in shifts. Obviously, if your character works a shift (like graves) they are already in uniform or in their vehicle or office and can respond accordingly. But, what about the CSIs who get called out after hours? This is where it can get a little interesting. During my career I worked banker hours during the day and was on-call at night and on weekends. Depending on the size of the lab you may be on-call as much as every other week or once every six or eight weeks. Usually you’re on call one week at a time. In some labs you may also be on “back up” the week before you go on-call which means you’re the number two person called if something major happens or the primary criminalist is already on a call out.
Most agencies will give you an on-call vehicle and some even supply your phone. You are required to drive this vehicle everywhere you go while on-call, even on personal errands like grocery shopping or going out to eat. Of course, when the call comes you have to finish up what you’re doing and respond to the crime scene. This adds a little inconvenience to your life in that you usually have to driver separately from your family. So if you and your spouse go out for dinner you need to drive separately. Same thing with going to the kids soccer game, Thanksgiving dinner, or anything else you might do. You can’t take your spouse or kids to a crime scene because you don’t know how long you’ll be tied up (days in extreme cases). Obviously, you have to stay somewhat close to home when on call. You can’t go camping for the weekend or do anything that would prevent you from responding in a reasonable amount of time. Most agencies I know of require you to be en route to a scene within thirty minutes of a call and on scene in about an hour.
Different agencies have different policies on who actually can call out a CSI. Most of the time this is restricted to the Sergeant rank or above. Since CSIs are a finite resource agencies don’t want them called out on every little thing so a higher ranked individual will evaluate the request to see if a CSI is really needed. In some agencies only the investigations supervisors can call out the lab and patrol officers must make their request through them. Either way, the CSI usually gets the call from either the ranking officer, detective, or in most cases dispatch. Regardless, when the call comes in you have to take down pertinent information about the crime. Every CSI will have a notebook and their phone on the nightstand or in their vehicle. Here are some of the basic things we might have to note as the call comes in.
- Time and date of the call out
- Who notified you
- The crime scene location (address)
- Initial details about the crime including secondary scenes (this information may be incomplete or incorrect depending on the source)
- Time and place of your departure to the crime scene (this could be your residence, restaurant, or some other location)
- Finally, time of arrival on scene.
Your departures and arrivals are usually done via police radio so there is a record. Every criminalist will be assigned a call sign number. Sometimes this is an arbitrary employee number, vehicle number, or just your name. Here is a hypothetical radio exchange between a CSI and dispatch. When you talk to dispatch you typically only reference yourself; you don’t have to say “dispatch”. There are some websites that actually let you listen in to live police radio traffic in your area so you may want to do a web search for your local police or sheriff followed by “police radio” and see what comes up.
CSI: “651″
Dispatch: “651 go ahead”
CSI: “Show me en route to 1234 4th street from my residence”
Dispatch: “Copy 2147″ (2147 would be 9:47 pm in military time)
Then when you arrive on scene you might say…
CSI: “651 on scene”
Dispatch: “2231″ (meaning your arrival is acknowledged at 10:31pm)
There is no need to acknowledge what scene you are arriving at because you already made that clear in the initial call. If you needed to talk to an officer or detective while en route you would contact them on the radio using their call sign followed by yours. For example you might say “Charlie 23, 651″. This means “hey guy named Charlie 23 this is me (651) and I want to talk to you.
Leuco-malachite Green Blood Reagent
Leucomalachite Green (LMG) was a popular blood reagent used from at least the 1950′s thru the 1990′s. I’m sure some CSIs may still use this reagent but it is not nearly as prolific today. Most US forensic supply companies don’t even sell the LMG reagent anymore. LMG has two primary uses in crime scene work. The first is as a presumptive blood test. LMG crystals are mixed with Sodium Perborate, water, and Glacial Acetic Acid (GAA). It’s this last component that made using the reagent a bit unpleasant. It’s the (GAA); it has a pungent vinegar odor which stinks to high heaven. The sensitivity of this reagent has been reported to be anywhere from 1:5,000 to 1:25,000 parts dilution. LMG is a good reagent for blood because it doesn’t have many false positive reactions. But, there are some concerns that the reagent is a carcinogen (cancer causing) and thus, it isn’t used much anymore. If you are writing a novel set in the 1950′s to 1990′s you can consider mentioning this reagent in your storyline. Watch the video below to see how the testing is conducted. The end of the video also has an interesting observation about the fluorescence of certain food items that may look like blood under normal lighting conditions.
Covering Bodies at Autopsy
I see this a lot on television and it really cracks me up. The detective comes into the autopsy suite and the victim’s genitalia or breasts are either covered with a small cloth or obscured by a bright spotlight. I understand why producers can’t show nudity on the major networks in the United States but I wonder if authors believe we actually cover up dead people’s genitalia at autopsy. The short answer is no. Dead people can’t get embarrassed. Detectives, CSIs, and pathologists are used to seeing naked dead people too; much worse actually. You can’t really avoid it while investigating death. In fact, every autopsy should include an examination of the genitalia including photography. Primarily this is to check for injury or disease that may be related to the cause of death or associated with a crime. We also have to search these areas for evidence like DNA, hairs, and fibers. It may be counter-productive to place a towel over a woman’s breasts if you need to swab them for touch DNA.
I’ve talked previously about the problems associated with covering dead bodies at crime scenes. Sometimes a cop or firefighter will cover a body because they don’t want the body visible to the family or public. This is especially true with bodies discovered in public places. We don’t encourage it but if your body is in the driveway of a house in front of a school bus stop (this happened to me) then you generally cut the cops a little slack. But these concerns don’t exist at autopsy. In fact, one of the first things we do at autopsy is remove the victim’s clothing.
A lot of authors have asked me about the circumstances in which we will collect sexual assault evidence. The truth is we collect samples in many cases which may not seem necessary. Most of the time we do it just to cover our bases. You only get one chance to get the evidence and the time and effort is inexpensive compared to an exhumation. Think of a traffic accident involving a teenage girl. Why might you search for sex assault evidence in such a case? What if the reason for her erratic driving was because she had been raped at a party before the crash? What looks like a tragic accident may have much deeper implications. CSIs always have to consider the improbable if we ever hope to discover it.
So if you are writing an autopsy scene make sure you don’t cover the body. Detectives, pathologists, CSIs, and attorneys are all professionals and we see naked people all the time. It comes with the territory.
The Autopsy Part I: External Examination
I can’t believe I haven’t written about this yet. Most of you have probably never been to an autopsy and while words alone can not provide the true flavor of the experience I think it may help to briefly explain the process. Coroners and Medical examiners usually perform an autopsy for any suspicious or unattended death. In the United States they do not need the permission from any person or entity to perform the autopsy. Most pathologists will be sensitive to certain religious or cultural protocols but they are not legally bound to adhere to them. One reason the medical examiner can perform and autopsy over the protest of the family is that family members may be suspects. Imagine how easy it would be to commit a murder if, as the spouse, you could prohibit the medical investigation into your wife’s death. That could be a real recipe for disaster.
In the United States we have a mixed system of Coroner and Medical Examiner offices. Most of these jurisdictions are defined by counties and major cities. Some may even be defined by judicial districts. Some rural states don’t have forensic pathologist and may have to drive a body to another state for an autopsy to be performed. Once the body arrives at the coroner’s office, the procedures may vary from case to case and office to office. Some pathologists want the body left sealed in the body bag until they begin the autopsy. This procedure may also happen with bodies sealed with an evidence seal in homicides. Other times an attendant or investigator may fingerprint the body prior to autopsy. They may also take x-rays and log in personal effects from the victim’s clothing. X-rays may show anything from foreign objects (choking), surgical devices, bullets, or even knife tips. Before any incisions are performed however, an external examination has to occur.
The external examination typically begins with photographs. We take pictures of the clothing, any visible injuries, and especially the face. It’s important to photograph the body from different perspectives. This is our one chance to get the body photographed properly. If we forget to photograph something we may never get a chance to go back. Just concerning the head we will take pictures of the face, right side, left side, neck, top, and back of the head. We may then take close-up photographs of injuries, jewelry, needle marks, and any distinguishing marks like tattoos, moles, or birthmarks. Then we remove the clothing and take a new round of photographs. It’s important to photograph the body from all sides and perspectives. Some areas that may get over looked include the soles of the feet, inside of the mouth, and a close-up of the neck.
The next step is the collection of evidence. The clothing is pretty easy. Most of it may get cut off but you have to make sure you don’t cut through any damaged areas. We also look for trace evidence. If the hands are bagged we’ll open those and scrape fingernails for trace DNA. We’ll also look for hairs and fibers, some of which may fluoresce with an alternate light source. If the victim died from a gunshot wound we’ll also look for gunshot residue. If there is any suspicion of a sexual assault then we will collect a “rape kit“. Once all the evidence has been collected then the body is washed. Dried blood and dirt is cleaned off and if any injuries are more visible they are photographed again! Check back in a bit and we’ll discuss the internal examination.
What are Petechiae?
Have you ever wondered how medical examiners can tell a person was smothered/strangled (asphyxia) if there is no ligature or damage to the neck? Although not 100% conclusive, the presence of petechiae can support such a finding. Figuring out how a person died can be pretty tricky if there isn’t some obvious trauma like a gunshot or knife wound. This is especially true if the victim is found in an otherwise benign setting, like in bed. Imagine finding an older woman dead in her bed. Imagine further she was in poor health. Is it possible the police could simply think the woman died from natural causes or some illness? Are there clues, so tiny, that they may be missed during casual observation? This is the reality that no CSI or detective wants to face and why autopsies are so commonly performed. Petechiae, also referred to as Petechial Hemorrhaging, are small pinpoint locations of bleeding where blood vessels have ruptured. They are most commonly seen in the eyes (and eyelids) but can also be found in the face, neck, and upper chest.
Sometimes they can be hard to spot. They are most easily seen against the white of the eye, but a trained forensic pathologist can easily spot them in other areas of the body as well. They can even be found on internal organs. These pin pricks occur when there is increased venous blood pressure. This is what commonly happens during asphyxiation. When a person’s airflow is cut off or restricted (smothering, suffocation, strangulation) the body struggles to breathe and move oxygenated blood to the vital organs. This increased pressure can be too much for the blood vessels and they simply burst open. Now this condition can also be seen in non-criminal deaths like drownings and certain heart failures so the presence of petechiae isn’t 100% conclusive for strangulation or smothering.
But if you are writing a scene in which a person dies (or is suspected of dying) from asphyxiation then you should consider mentioning petechiae. Of course, if the scene has been staged to look like a suffocation (such as placing a plastic bag over their head) but there is no petechiae then your detective characters should make note of the lack of petechiae. Petechiae is also very difficult to see in advanced stages of decomposition. In such cases the medical examiner may have to look for other evidence that might indicate strangulation such as ligatures. You could write a scene in which the petechiae are overlooked by a small town Coroner or inexperienced police investigator only to be discovered later by the state Medical Examiner. Of course, by that time the suspect may have had time to flee the area or get rid of incriminating evidence leaving your detective back at the drawing board. You could even have the victim’s body cremated and then your detective spots the petechiae in a photograph or from a notation in a report that describes a “rash”. Without the body it would only be speculation but it might cause your detective to suspect foul play where none existed before. The options are almost endless so have fun experimenting with different scenarios.
Searching for Trace Evidence Part 3: The Victim
I have written previously on the search for trace evidence from the crime scene and suspect and now it is time to talk about the victim. CSIs search for trace evidence because it serves as a powerful tool to link a suspect, victim, and crime scene together. Many violent confrontations between victim and suspect will result in an exchange of trace evidence. Victims may also retain trace evidence from a crime scene or secondary location. Whether alive or dead there are certain areas that may yield valuable evidence depending on the type of crime and actions of the suspect. trace evidence is generally collected by either swabbing, forceps, or adhesive lifters. Here are a few places CSIs routinely search for trace evidence on the victim.
Hands:
- Suspect DNA may be found under the victim’s fingernails. Scraping or cutting the nails are the preferred methods for evidence collection.
- Suspect hairs or fibers may also be caught up in jewelry like watches and rings, especially if there was a struggle. Hairs may also be found in the clenched hands of a deceased victim.
- “Touch” DNA may also be found on the victim’s hands, especially if the victim had significant contact with the suspect’s skin during a struggle.
- These locations may also contain soil, fibers, pet hair, or vegetation from one or more crime scenes.
Fluorescent markings
- Broken Fingernail
Hair:
- Victim hair (head and pubic) can easily retain everything from suspect hairs, vegetation, carpet fibers and the like helping to link the suspect, vehicle, or crime scene.
Mouth:
- Victims may sometimes bite the suspect and in the process skin or DNA can be transferred or retained in the teeth or on the lips. In some cases foreign objects like fabric gags, tape residue, even gravel may be found.
Genitalia & Breasts:
- Genitalia may be an excellent reservoir for trace evidence including semen, even after a victim has showered or bathed. Body cavities are generally swabbed to recover DNA but examiners should also consider that foreign objects like knife tips, vegetation, or other items may also be found.
- In some sexual assaults a female breasts may contains suspect DNA which can be swabbed.
Clothing:
- Victim’s clothing can hold trace evidence just like suspect clothing. Shoe tread can retain dirt, vegetation, hairs/fibers, even blood. Velcro straps on shoes (or anywhere else) can also be a great trap for trace evidence.
- Pant cuffs and pockets are also great locations to search.
Other Locations:
- Stomach contents. I’ll be writing a specific post soon on stomach contents but suffice it say, sometimes victims ingest things during a struggle which can include suspect body parts or foreign objects.
- Ears and nostrils may sometimes contain hairs, fibers, even soil or vegetation from a crime scene.
- Maggot masses. This is an often overlooked location. When medical examiners or entomologists scoop up large samples (or individuals) of insects they may also inadvertently be collecting hairs or fibers clinging to the insects as they crawl across the body.
Ashes to Ashes: Do Arson Fires Really Destroy a Body?
This is a question I get from time to time so today I have a guest posting here to discuss the issue. A lot of people mistakenly believe that it is easy to completely destroy a body with fire; and while you can certainly do a lot of damage, destroying it completely is very difficult. It’s easy to think that fires are so destructive because we see what they can do to houses, forests, and the like but the truth is a bit more complex. If you have a scene like this in your novel stop on over at Stuff & Non-sense to take a look.
The Color of Fly Puparia
I’ve written before about maggots and how Forensic Entomologists use insect evidence in murder cases. Once maggots are done feeding on a body they will enter a pre-pupal or wandering phase and migrate to a safe place to pupate. The puparium is better known as a cocoon. It is the hardened cuticle (skin) that protects the pupa during its metamorphosis from a maggot to the adult winged fly. Maggots will spend approximately two-thirds of their immature life in this stage before emerging as an adult. During this time the puparium will go through several color changes.
Maggots are a milky white color prior to this stage so it makes sense that the initial pupal stage is a whitish-yellow color. As the maggot ages the cuticle will darken in color. After yellow, the casing will turn a reddish-rust color then brown. At first it might be a lighter brown and then darken to a deeper brown. At this point the adult fly will usually emerge by pushing through one end of the casing.
The pupal casing is extremely durable and can persist in the soil for thousands of years. Archaeologists have actually used ancient pupal casings to help identify the season of death at sites of bison kills and other dead animals in a similar way to a forensic examination. Fortunately, most murder investigations are much younger in age. The best way to use these color changes in your novel is through photography or personal observation by the detective.
Over the years I have had several cases where the pupal cases cold be seen in photographs but were not collected. Most of the time this is because detectives just didn’t recognize them as evidence. But if the cases are yellowish then I know they are at the beginning of their development. If they are dark brown to black they are much further along. It’s not exactly a precise measurement but it’s usually better than having just the maggots from the body. You may not even have photographs and instead have to rely on the visual observations of officers or detectives. Again, not ideal, but it’s usually better than nothing.
You can get pretty crazy with your descriptions or dialog. Detectives sometimes refer to these casings as rodent droppings. I’ve heard of cases where the detectives will actually take them to a wildlife biologist or scat expert in an attempt to determine what animal dropped them. I’ve often wondered how such an expert wold react if they were told the scene was littered with yellow droppings. It might take them a while to figure out that the evidence was from insects and not rodents! However you choose to use this information just remember that color changes can vary and aren’t as precise as other aging methods.
The Armchair Detective: Unusual Marks
This is the second installment of The Armchair Detective series. Remember, there are no “wrong” answers. This exercise is designed to get your creative juices flowing and hopefully pull you out of any creative ditch you may be stuck in. Here is the fictional scenario;
There have been at least three rapes over the Winter months wherein the suspect forcibly enters the victim’s ground floor apartment. The male suspect enters by prying open sliding windows after removing the screen. Once inside he makes his way to the bedroom and covers her mouth with whatever he can find (victim’s clothing). He then rolls them over and presses a “weapon” into their back. The women couldn’t identify the weapon but said it was cold, heavy, and solid like steel. The women were not injured by that object and showed no “marks” on their skin. The victim’s report that the man wore all black including a face mask and leather gloves. The suspect has worn a condom and the rape kits have come back with negative or inconclusive results. One woman remembered a strong cologne but didn’t know what brand it was. Two of the women originally didn’t report the rape but revealed the crime to friends days later. Detectives are sure there are other rapes not being reported but they don’t really have much to go on.
The police set up a tip line and one unknown woman called in to say a man she dated acted strangely including wanting to “role play” a rape. The man did live within a five mile radius of the victim’s homes so detectives decided to pay him a visit. They found the man working on his car in the garage and he invited them in to talk. The man vehemently denied having anything to do with the rapes. While the detectives talked to him they spotted some strange marks on the garage floor and took a quick photograph before being asked to leave. The marks had general class features but no identifiable marks. Here are some questions. Do you have a theory as to what caused the marks, are they important, and can they be used to search for other similar cases? The ruler in the photograph is 13″ (32.5cm) long
Leave your comments below and I’ll chime in after a few days.
Unknown marks on garage cement floor
