Introduction to Gunshot Wounds

This page will mark the beginning of one of the big topics in forensic pathology: gunshot wounds. A forensic pathologist must be an expert in recognizing and classifying gunshot wounds accurately. Gunshot wounds, whether inflicted via suicide or homicide, are extremely common in the United States.  As usual, we’ll pull some quick numbers from the CDC Web Based Injury Statistics Query and Reporting System (WISQARS).

Filtering these numbers by manner of death looks like this:

You’ll notice that most firearm deaths in the United States are suicides and most of the remainder are homicides. Legal intervention refers to police-involved shootings and are a minority of cases. As we covered here, firearm deaths that are truly accidental are pretty rare. The same goes for cases classified as “undetermined.” So far in my career, I’ve only had one case of a firearm death that was classified in this way.

So how does the US compare to the rest of the world? Unsurprisingly, we have a relatively high firearm-related mortality rate. Overall, we are 31st in the world in terms of number of deaths. We have the highest rate of firearm death compared to other countries of similar socioeconomic status by a pretty good margin. We’re not so concerned with this as it doesn’t relate directly to forensics. My point is that firearm deaths are very common in the United States, which is why we have to be well versed in their classification. If you’d like to read more, NPR has a good article on the subject. You can take a look at the data that they used for that article here. I know this can be a touchy topic in the United States, so we’re going to focus mainly on the science.

As I mentioned, this is a huge topic in forensic pathology, so I think we will break it down into smaller pieces like this:

• Firearm basics
• Ammunition basics
• A quick word about ballistics
• Wounding due to gunshot wounds

The last section will be the meatiest as that will describe how we classify and document the actual wounds. Also, just as a note, there will be some graphic images included in these lectures, so be forewarned.

First, let’s take a big picture view of the gunshot wound case.

The Role of the Forensic Pathologist

All medical tests and procedures are performed with the goal of providing answers to specific questions. Our practice is no different. When we have gunshot wound cases, here are some of the questions that we try to answer:

• Is it reasonable to conclude that the gunshot wound cause death?
• If no, what other factors contributed?
• Does the wound morphology match the circumstantial information?
• What structures were injured by the projectile?
• Does the decedent have any natural disease?
• Was there any interaction between the injury and said natural disease?
• What evidence needs to be collected?

As you can see, this information can be garnered via the usual methods. A combination of good investigation, medical record review, and autopsy findings will provide the information you need in complex cases. 

Since most gunshot wound deaths are suicides, let’s start there.

Suicidal Gunshot Wounds

The investigative information in these cases is usually straightforward. Autopsies may or may not be done, depending on the local practice. There are increasing numbers of older men committing suicide by this method, and they often have well-documented medical histories. These cases in particular may only require examination of the wound morphology. While we are on the topic, let’s look at some factors that are consistent with a suicide.

• Evidence of one round fired
• Firearm on or near body
• Single gunshot wound on body that is usually contact or near-contact
• Presence of a suicide note

It may seem kind of silly to point out such obvious stuff, but being in the habit of a having a systematic approach is always helpful. More often than not, suicidal gunshot wounds are gunshot wounds of the head and are self-evident. The don’t usually require too much extra work. However, let’s look at a case that’s a little less straightforward:

Example #1: A Determined Suicide

A 25 year-old man has a long history of depression that has been complicated by multiple prior suicide attempts. This seems to have stemmed from a car accident a few years ago that left him with chronic pain. He lived alone in an apartment complex not far from his parents’ house. They usually hear from him on a daily basis, so they become concerned when he misses a phone call. His mother goes to the apartment and lets herself in with a key. Inside, she finds her son deceased on his bed.

Investigators respond to the scene and they discover a defect on the right side of his head, specifically in the parieto-occipital area. Roughly here:

A .40 caliber handgun is found in his right hand. His mother confirms that this is his dominant hand. Elsewhere in the apartment, this is discovered:

The body is transported to the medical examiner’s office for examination. You clean the wound and find this:

I know we haven’t covered this yet, but take my word for it that this is an atypical entrance wound. Furthermore, when you remove the clothing, you find this:

You count 7 of these on the body in total. Let’s recap our information so far:

• We have a case that is circumstantially a suicide
• This is supported by a suicide note and the decedent’s medical history
• Was the gunshot wound sufficient to cause death?

Here’s where we get a “maybe.” The wound looks superficial and lacks the quality of a contact gunshot wound, which is usually seen in suicides. Furthermore, there’s a big confounding factor here: the fentanyl patches. So, you decide to perform an autopsy.

Looks pretty uninjured to me. It certainly is not affected by a gunshot wound. There are no other injuries. But, we have one more tool at our disposal that will help here: toxicology. Our tox results reveal a fentanyl concentration of 25.6 ng/mL. That is enough to cause death in and of itself. So how would you certify this? If you need to, refer back to back to the death certification lecture before you scroll down. Here’s how I would do it:

And of course the manner is suicide. My reasoning is that the gunshot wound may or may not have killed him. Without medical intervention, progressive edema associated with the concussive force of the bullet probably would have caused his death,  but people have survived more damaging injuries. What if he had recovered enough and decided that he wanted to seek medical help? Is there something else that would have prevented this from happening? The answer is yes: the fentanyl patches. The gunshot wound is what started the whole process, and the fentanyl toxicity is what kept it going, hence the death certificate above. Why have I left the interval blank? There’s no way for me to know if minutes or hours passed between the injury and death and I’m not going to guess.

That’s about as complex as suicides get. Let’s take a moment to talk about homicides.

Homicides

The major role that medical examiners play in homicide investigations is evidence procurement and injury documentation. We collect a variety of physical evidence during the course of the case. Here are some examples

• Clothing
• Fingernail clippings and scrapings
• Buccal swab (usually used as a DNA standard for the decedent)
• Pulled head hair
• Sexual assault kit, if the case requires it
• Projectiles in the clothing or in the body

The majority of homicides require a full autopsy. It’s the best way to procure enough information to answer all our questions. However, we may choose not to perform an autopsy in certain cases. For example, if a long period of time has passed between the injury and death, performing an autopsy may not provide you with more information than can be garnered from police reports and medical records. Physical evidence certainly won’t be obtainable at that time.

Projectiles are probably the most important things we recover. They have high evidentiary value. We’ll cover that later. Suffice to say that if there’s a bullet in a body, we’re probably going to go get it.

Autopsies in homicide cases can get pretty technical in terms of special dissections that must be performed to properly document injuries. Autopsy practice aside, one thing that most people may not realize is that there is a lot of effort that goes into properly documenting, storing, and transferring evidence. If this is done incorrectly, it can hamper the prosecution. It really should be those with dedicated forensic pathology training that handle these cases.

Let’s cover one more technical point before we finish. I’m talking about wound trajectories.

Wound Trajectories

Most crime procedural shows include a scene where the ME provides an incredibly detailed account of the terminal event that is sometimes accompanied by a blurry re-enactment. He also calls the decedent “the vic.” Unless he was the one that shot “the vic,” neither of these things happen in real life.

Documenting wound trajectories can take a number of forms, but is always included in an autopsy report. One common practice is the use of long probes to connect wounds that are related. This might look like this:

Personally, I am a little hesitant to probe through a body cavity before I know what’s going on inside. It is easier than you think to create extra holes or alter trajectories by blindly probing. I prefer to take sequential photographs of injured structures, and if anyone has any questions about it, they can always ask about it in a deposition or during testimony.

Summary

In conclusion, gunshot wound cases are common and encompass an important part of our work. Most are suicides. Homicides can be difficult cases that require a careful eye for detail. The main goal in both is to answer the questions we raised in the beginning of this section. Next, we’ll talk a little bit about the basic mechanics of firearms.