What are the steps for forensic examination and treatment of ballistic injuries?

Forensic Examination of Ballistic Injuries

For forensic examination of ballistic injuries, begin with meticulous preservation of evidence including photographing all wounds, cutting around (not through) bullet holes in clothing, and documenting precise wound characteristics before any treatment, while simultaneously performing CT with IV contrast in hemodynamically stable patients to map projectile trajectory and identify all injuries. 1

Initial Evidence Preservation (Medicolegal Priority)

• Photograph all entrance and exit wounds with precise documentation of location, size, and characteristics before any intervention 2
• Preserve all clothing by cutting around bullet holes rather than through them, as this destroys critical forensic evidence 2
• Collect and secure all metallic foreign bodies recovered during treatment and immediately turn them over to law enforcement officials 2
• Document wound characteristics including stippling, powder burns, soot deposition, and abrasion collars that indicate firing distance 2
• Maintain chain of custody for all ballistic evidence removed during surgical procedures 3

Hemodynamic Stratification (Determines Imaging vs. Immediate Surgery)

• Assess hemodynamic stability first: systolic BP ≥90 mmHg and heart rate 50-110 bpm determines whether imaging is performed or patient proceeds directly to surgery 1, 4
• Unstable patients (SBP <90 mmHg) require immediate surgical intervention with only bedside FAST examination and portable radiographs performed during resuscitation—do not delay surgery for CT 1, 4
• Stable patients proceed to comprehensive imaging evaluation to map trajectory and identify all injuries 1, 4

Imaging Protocol for Stable Patients

Primary Imaging Modality

• CT chest, abdomen, and pelvis with IV contrast is the standard imaging tool providing up to 99% negative predictive value for triaging hemodynamically stable patients 1
• Use whole-body CTA (arterial and venous phases) because multiple injuries and active bleeding are common, and bullet trajectories are unpredictable 1
• CT with IV contrast identifies vascular injuries (pseudoaneurysms, intimal flaps, filling defects, contrast extravasation), organ injuries, and precise missile trajectories 1

Trajectory Mapping

• Single-acquisition whole-torso imaging is preferred over segmental imaging so the complete bullet tract can be followed 1
• Use multiplanar reformations to precisely map the projectile path through tissue planes 4
• Pay special attention to the "cardiac box" (sternal notch to xiphoid, nipple to nipple) as injuries here cause rapid decompensation 1

Initial Radiographic Assessment

• Obtain trauma radiography series to identify retained ballistic fragments, suggest trajectory, and detect pneumothorax, hemothorax, rib fractures, and mediastinal injuries 1
• Radiographic markers should be placed at all skin entry/exit sites before CT to aid trajectory analysis 1

Wound Ballistics Principles for Forensic Assessment

• Distinguish high-energy (gunshot) from low-energy (stab) injuries: gunshot wounds have mortality of 13.7 per 100,000 with only 4.3% survival after emergency thoracotomy, while stab wounds have 15.2% survival 4
• Assess for blast effect: gunshot wounds produce tissue disruption up to 2 cm from the bullet path even without direct contact 1
• Evaluate temporary cavitation zone: the myth that all tissue in the temporary cavity requires excision is false—only visibly damaged tissue needs debridement 5, 6
• Document whether wounds are through-and-through (entrance and exit) or retained projectile 2

Critical Forensic Documentation Elements

Entrance Wound Characteristics

• Measure and photograph wound diameter, shape, and margins 2
• Document presence/absence of stippling (unburned powder particles in skin, indicates <2 feet firing distance) 2
• Note soot deposition (indicates contact or near-contact wound) 2
• Identify abrasion collar (rim of abraded skin around entrance) 2

Exit Wound Characteristics

• Exit wounds are typically larger and more irregular than entrance wounds 2
• Document size, shape, and tissue damage pattern 2
• Note that exit wounds lack stippling, soot, and abrasion collars 2

Projectile Recovery

• All recovered bullets, fragments, and foreign bodies must be preserved and transferred to law enforcement with documented chain of custody 2, 3
• Handle metallic fragments minimally to avoid damaging ballistic markings 2

Mandatory Reporting Requirements

• 48 of 50 U.S. states mandate healthcare providers report ballistic injuries to law enforcement regardless of when the injury occurred 3
• Reporting timelines, fines for non-compliance, and potential imprisonment vary by state jurisdiction 3
• Delayed presentation of chronic ballistic injuries still requires reporting in most jurisdictions 3
• Violations of mandatory reporting may result in fines or criminal charges depending on state law 3

Common Forensic Pitfalls to Avoid

• Never destroy clothing by cutting through bullet holes—this eliminates critical trajectory evidence 2
• Do not assume high-velocity wounds require extensive tissue excision beyond visibly damaged areas—this is a debunked myth 5, 6
• CT misses bowel injury in 20% of cases initially—patients with equivocal findings require admission for serial examinations 4
• FAST examination requires approximately 620 mL of free fluid to be detected and is non-specific for intestinal injury 4
• Noncontrast CT is inadequate for evaluating vascular injuries in ballistic trauma 1

Special Anatomic Considerations

Genitourinary Injuries

• Penetrating injuries (especially gunshot wounds) account for most ureteral injuries, with blast effect extending 2 cm from bullet path 1
• Bladder injury occurs in 3.6% of abdominal gunshot wounds and 20% of penetrating buttock injuries 1
• CT with delayed excretory phase is required for follow-up of ureteral and bladder injuries 1

Mediastinal Injuries

• CTA chest guides immediate surgical intervention versus expectant management for transmediastinal injuries in stable patients 1
• CTA decreases need for routine angiography and esophageal studies in mediastinal gunshot wounds 1