Bringing Evidence to Light

A patient presents to the emergency department with a complaint of domestic violence who reports having been “choked.” She has no visible injuries and did not pass out…

This scenario plays out countless times each day and illustrates how victims of manual strangulation (the most common type) are at an extreme disadvantage because their injuries are seldom visible to the naked eye.

This may create challenges for medical care providers in assessing the acuity of a patient’s injury and treating those which are potentially life-threatening.

The forensic nurse examiner (FNE) program at Mercy Medical Center in Baltimore uses light source technology that can identify bruising and other wounds at a sub-dermal level, enabling care providers to more effectively treat patients who have been strangled.

Mercy’s FNE program is the designated center in Baltimore City for the assessment of survivors (>13 years of age) of sexual assault and other forms of interpersonal violence.

Thirty-one forensic nurse examiners cover a 24/7 schedule and staff a mobile unit that brings forensic medical care to victims considered too injured or acute to be transferred to the medical center where the forensic program is located.

FNEs obtain forensic medical interviews, perform forensic medical assessments, procure evidence and offer crisis intervention.


Wings of a DOVE

Unique protocol educates hospital staff about strangulation.

Alternative Light Sources

In 2006, Mercy began a search to offer solutions to concerns surrounding the care of patients who reported being strangled, as medical personnel had no definitive protocol stipulating when to request CT scans, soft-tissue films and other studies of the neck on these patients.

Documentation at many facilities was found to be subjective and lacked detail in presenting versus resolved symptoms of the assault.

Many times these patients were brought to the ED by police as victims of violent strangulation crimes, when the police were not able to discern who the victim was and who the perpetrator was.

Medical personnel had little to go by when there was no visible injury, and when initial symptoms had already resolved.

As a result of our inquiries, the Mercy FNE program pioneered the use of an alternative light source (ALS) for use in forensic medical examinations in Baltimore City.

A forensic light source consists of a powerful lamp that emits ultraviolet, visible and infrared wavelengths. It filters the light into individual color bands (wavelengths) that enhance the visualization of evidence by light interaction techniques: fluorescence (evidence that glows); absorption (evidence that darkens); and oblique lighting (small particle evidence that is revealed).

Goggles are used to filter out the intense reflection and these light sources can reveal bruises and patterned wound details that are invisible to the naked eye. These lights range in price from $2,000 – $10,000 and require no calibration and little maintenance.

Strangulation Process


Strangulation, a violent, intentional act, is defined as “a form of asphyxia characterized by closure of the blood vessels or air passages of the neck as a result of external pressure.”1

It may be inflicted by one of two methods:

manual strangulation, also known as “throttling,” involves a one- or two-handed chokehold; and

ligature strangulationalso known as “garroting,” is imposed through the use of a cord, rope or clothing to compress the neck.

Garroting can be further divided as hanging (using the body weight to compress a ligature) and autoerotic (self-induced asphyxiation for sexual gratification).2

Often we see that when an arm or hand exerts pressure on the neck, capillary beds under the skin are usually not disrupted, but the absence of bruising does not mean an assault did not occur.

Although the neck is a relatively unprotected region of the body, it contains the primary structures that support life-sustaining processes.

Survivors often report the following signs and symptoms either during or after the assault: dizziness, visual changes; loss of consciousness; headache; tinnitus; coughing; nausea/vomiting; involuntary loss of bladder or bowels; petechial hemorrhage (notably in the eyes, on the gum line and behind the ears); muscle spasms; memory loss; shortness of breath; and syncope or near syncope.3

With the understanding that carotid arteries which supply oxygen to the brain are relatively close to the surface of the neck and are afforded little protection, the neck is vulnerable to life-threatening and irreversible damage when pressure is applied.

Referral to a Forensic Program

Screening of all patients for interpersonal violence in the home as well as in dating relationships is mandated by the Joint Commission.

When a patient reveals they have been strangled, and there are no obvious wounds visible, referral for safety may be the next step for the practitioner, but further evaluation for medical care should be considered.

After a medical screening, use of the ALS, or referral to a forensic medical program that utilizes this technology, may be the next step in further treatment and effective diagnosis of the patient’s medical status.

Victims of domestic violence are frequently dismissed because their injuries are often not visible to the naked eye. In fact, the victim may be the person arrested because while they were fighting for every breath, they display no injuries where the perpetrator may have scratch wounds.

Victims of strangulation are difficult to assess in the ED for the same reason – their injuries may not be visible to the naked eye. Small leaks in the vascular system can have severe long-term implications if they are not diagnosed in a timely fashion. Indeed, swelling may still be taking place 24 hours after the assault.



Technology to assist in better patient care.

Performing an MRI or obtaining a CT scan on every strangulation victim can be expensive, time consuming and not an appropriate use of medical resources. The use of an ALS combined with symptomology can both demonstrate injury and indicate which patients need further studies.

FNE programs are available in both urban and rural areas across the U.S. Many of these programs have expanded services to include care to victims of interpersonal violence other than sexual assault.

It is important for all first responders and ED nurses to know the scope of practice for your regional forensic nursing program and the protocols for patient referral.

FNE programs have become an integral part of emergency medicine and are fully equipped to assess injuries and perform evidentiary examinations.

In addition, FNEs are an excellent conduit for evaluating victims of interpersonal violence.

References for this article can be accessed here.

Debra S. Holbrook

is coordinator of the forensic nurse examiner program at Mercy Medical Center in Baltimore.

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