Case Study: One Impressive Projectile
Written by Dr. Jennifer Johnson   

Article courtesy of the Academy of Forensic Nursing

This article appears in the July-August 2021 issue of Evidence Technology Magazine.
You can view that full issue here.

FORENSIC NURSE EXAMINERS and medical professionals may encounter patients who have sustained gunshot wounds. They may be either self-inflicted or inflicted by others. The forensic nurse examiner evaluates the patient along with other medical providers who may be providing life-sustaining medical interventions.

A key assessment outcome is to assure proper interpretation of the wound(s), obtain photographs of the physical presentation both before and after medical intervention, and clean the injury. The forensic nurse assures appropriate handling of valuable forensic evidence, including the patient’s clothing and the retained projectile, while maintaining chain of custody. Ultimately, the forensic nurse will provide their findings within the medical record to assure there are no erroneous identifications of the entrance and or exit wounds which could cause profound issues in subsequent legal proceedings.

Gunshot wounds provide a wealth of information just by focusing on wound patterns, range of fire, and trajectory. Gunshot wounds are either penetrating, where there is one single entrance wound and no exit, or perforating, where there is both an entrance and an exit wound. Beyond the entrance and potential exit wound, there are many other physical characteristics that may be present during evaluation. Rather than the size of the wounds, other physical characteristics will aid in differentiating between the entrance and exit wounds.

Entrance wounds have six physical findings that may be present:

1) The abrasion collar, which is caused by the projectile entering the skin. An abrasion collar may be circular in fashion; however, if the projectile is traveling and enters the body at an angle, this will result in an angled or comet-tail abrasion collar because the bottom side of the projectile has more contact with the skin. This type of abrasion collar can provide information about trajectory and the direction the projectile was traveling through the body.

2) Another physical finding is tattooing or stippling which can be caused by unburned gunpowder.

3) If the gunpowder is burned, then the carbon abrasion residue called soot may be present on the skin, which may be wiped away. Soot can make direct visualization of the abrasion collar difficult to the examiner. The recommended practice would be to photograph the injury as it appears, and then wipe away the soot to visualize the abrasion collar, and then obtain additional photographs. Soot will only be present in those gunshot wounds that are close range of fire.

4) The skin may be seared from the flame emitted from the barrel of the gun, or 5) triangular shaped tears may form from the gas that has been injected into the skin, causing the skin to expand to a point where it rips and tears.

6) In some instances, there may be the presence of a muzzle contusion which results from the injected gas pushing the skin against the barrel of the gun itself.

Exit wounds may also have irregular borders, even though there may be an absence of soot and seared skin; there is a possibility of having no tattooing or stippling apparent, but still presenting with the triangular shaped tears.

Range of fire is the distance from the gun to the impacted anatomical location on the body. The range of fire will also present physical characteristics at the wound location. Contact with the skin, even through clothing, will result in an abrasion collar, seared skin, triangular shaped tears, and the presence of soot. Close contact, which is zero to six inches, will result in the presence of an abrasion collar and the presence of soot. Intermediate range of fire, which is up to 48 inches, will present with an abrasion collar and tattooing or stippling. Distant indeterminate range of fire is greater than 48 inches and the singular physical finding will be that of an abrasion collar.

When the examiner assesses an individual that has sustained a gunshot wound, the examiner notes the entrance and exit wound characteristics, identifies the range of fire based on the physical characteristics noted, and then identifies the trajectory of the projectile. Trajectory is the path taken by the projectile into and through the body to its resting place, either inside the body or through an exit wound. This is documented as superior to inferior, medial to lateral, and anterior to posterior in relation to the entrance and exit wound.

When evaluating an individual who has sustained a gunshot wound, there are some important questions to ask:

  • What happened?
  • Was the individual facing toward or away from the gun?
  • Who shot them?
  • If you are familiar with types of guns, what type of gun was used?
  • How many shots were heard?
  • Does the individual know why they were shot?
  • Does the individual with the gunshot wound own a firearm?
  • How far away from the gun were they?

These questions will aid in the evaluation of the wound, and either corroborate or refute the information being disclosed.

An Unusual Case Study

It is not every day that an examiner evaluates an individual with two entrance wounds and two exit wounds. The following case will showcase the physical presentation of a self-sustained gunshot wound. A man in his 20s presented to the emergency department after a gunshot wound. He described placing the firearm into the front right pocket of his jeans. The gun discharged and the projectile traveled superior to inferior and from lateral to medial through his right testicle and exited through his left testicle. In this case, there was contact with clothing, as the firearm was located within the front pocket. Gases were injected into the pelvic area where the barrel was located. The gases that were ejected were caught between the pocket liner and the underlying skin. As such, not all the gases went into the wound, but on the surface of the skin the presentation of seared skin, soot, and triangular-shaped tears was noted. The pocket liner expanded, and the flame as well as the bullet made contact with the skin, resulting in additional injury.

The following pictures depict the wound presentations identified during the medical forensic evaluation.

This image shows the entrance wound at the base of the right testicle, at the ten o’clock position. Notice the soot and seared skin that is present. Close examination shows there are triangular shaped tears present as well.

The projectile traveled through the testicular region and exited through the left testicle at the four o'clock position. Note the absence of seared skin and soot; there is no stippling present; and there are some definitive triangular shaped tears visualized on the superior portion of the wound.

Inside the right-front pocket liner, bullet wipe and fiber defects were visualized. Bullet wipe residue transfer caused when the projectile passes through the pocket liner. The bullet wipe forms when the carbon residue present in the barrel is transferred onto the projectile as it travels downward, which is then deposited on the pocket liner. The bullet, which was a soft-nosed lead without a jacket present, travels down the barrel and the lead wipes off onto the clothing.

Primer residue was noted. This arises when the projectile is discharged and a puff of residue from the primer is expelled initially out of the barrel and is deposited on the pocket liner. There is also an absence of projectile lubricant, which is an oil that may be deposited onto the projectile while it is located either in the magazine or the chamber. When the projectile is discharged, the lubricant then travels down the barrel and makes contact with the right pocket liner.

Interestingly, the projectile then re-entered through a comet tail abrasion collar and traveled inferiorly down the inner aspect of the medial aspect of the left thigh and then exited. The projectile was ultimately located within the residence.

Because of the anatomical location of the injuries, the gunshot wound victim was subsequently transported after stabilization for additional evaluation and treatment in a trauma center under the care of a urologist.

This case study is a fascinating look at the travel path and the injuries left behind. To have all the injury presentations visualized on the skin—minus tattooing or stippling—was, in this authors and examiner’s opinion, a once-in-a-lifetime case presentation.

Editor's Note: In the October issue of Evidence Technology Magazine, Dr. Jennifer Johnson will provide an article on packaging evidence collected from gunshot wound individuals.

About the Author

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it is a board-certified women’s health nurse practitioner, board-certified advanced forensic nurse, and sexual assault nurse examiner with more than 20 years’ experience in practice. She previously developed and managed a comprehensive forensics program in the Midwest and is the president and owner of Johnson Legal Nurse Consulting, LLC. Johnson is an appointed member of several professional and governmental organizations related to forensic nursing, including the National Institute of Standards and Technology/National Institute of Justice Evidence Management Project, and is the President Elect and a Co-Founder of the Academy of Forensic Nursing.

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