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Shot sequence detection aided by postmortem computed tomography in a case of homicide
Journal of Forensic Radiology and Imaging 1 (2013) 68–72
Contents lists available at SciVerse ScienceDirect
Journal of Forensic Radiology and Imaging journal homepage: www.elsevier.com/locate/jofri
Case report
Shot sequence detection aided by postmortem computed tomography in a case of homicide Patricia M Flach a,b,n, Garyfalia Ampanozi a, Tanja Germerott c, Steffen G Ross a, Astrid Krauskopf a, Michael J Thali a, Michael T Mund a a
Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland c Institute of Forensic Medicine, Medical School Hannover, Hannover, Germany b
ar t ic l e i nf o
a b s t r a c t
Article history: Received 1 November 2012 Received in revised form 21 March 2013 Accepted 22 March 2013
This study investigated the use of postmortem computed tomography (pmCT) in a homicide victim with three gunshots. This case report illustrates that pmCT enhances the forensic investigation and facilitates dissection of complex regions like the neck and may aid in the determination of a possible chronology of successive shooting. Postmortem imaging should be included as an established standard protocol in any state-of-the-art gunshot injury examination in forensic pathology, as this imaging method may provide more information than autopsy alone. & 2013 Elsevier Ltd. All rights reserved.
Keywords: Virtopsy Gun shot Homicide PmCT Postmortem Computed tomography Autopsy
1. Introduction The use of 2-dimensional radiography for gunshot wounds is well established in forensic medicine. However, the role of radiology in a forensic examination has expanded during the past decade to include postmortem computed tomography (pmCT), pmCT-angiography (pmCTA), image-guided biopsy and magnetic resonance imaging [1–5]. The virtual autopsy (“Virtopsy”) is particularly advantageous in gunshot victims, as pmCT is a non-invasive technique that aids in the detection and precise spatial localization of foreign bodies such as metallic fragments or projectiles and guides the forensic pathologist during bullet retrieval [6–8]. In addition, 3-dimensional pmCT can be used to document the bullet path(s) by depicting typical gunshot wound fracture patterns, discriminating osseous entry and exit wounds and evaluating any associated tissue damage prior to autopsy [9–14]. Additionally, the shooting direction, number and type of shots (e.g., penetrating, perforating, grazing, or self- or foreign forceinflicted), firing distance and an inference of the weapon and ammunition are of forensic interest. The investigation should also detect the source of immediate incapacitation and the manner and
n Correspondence to: Institute of Legal Medicine, Virtopsy, University of Zurich, Winterthurerstrasse 190/52, 8057 Zurich, Switzerland. Tel.: +41 44 635 5611; fax: +41 44 635 6851. E-mail address: patricia.fl[email protected] (P.M. Flach).
2212-4780/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jofri.2013.03.045
cause of death. This report of a homicide case delineates the feasibility of pmCT prior to autopsy to determine the precise anatomy and maybe even chronology of successive gunshots.
2. Case history A 55-year-old woman was shot by her husband three times in a public place and succumbed to her injuries at the crime scene.
3. External inspection The corpse presented with sparse livor mortis. Shot number 1: A position-dependent blood track was observed at the right ear with a cartilaginous and soft tissue burst of the right earlobe, which was consistent with a perforating shot. A retroauricular longitudinal abrasion was the result of a grazing shot. Shot number 2: Crepitation was detected in the right mandible with palpable soft tissue emphysema in the left midface, neck and thorax. An oval defect (5 mm) with an abraded appearance (1–4 mm) and powder stippling on the skin of the right mandible was compatible with an entry wound, and a larger
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Fig. 1. (A) View of the right side of the cheek. The image depicts an oval defect with an abraded appearance on the right mandible that is compatible with an entry wound. Note the hemorrhage at the right earlobe due to the perforating shot. (B) Magnified view of the entry wound of the gunshot. (C) View of the left side of the neck. Note the enlarged adaptable slit-like defect on the left distal neck, which is consistent with an exit wound. (D) Magnified view of the gunshot exit wound.
(1 cm), adaptable slit-like defect at the left distal neck was consistent with an exit wound (Fig. 1). Shot number 3: A “cracked pot” sound in the skull and right occipitoparietal galeal swelling with an oval (5 mm) non-adaptable soft tissue defect consistent with an entrance wound were detected. There was no other exit wound detectable. No additional relevant findings were observed. 4. Imaging The corpse received a full-body dual-source pmCT scan (SOMATOM Definition Flash, Siemens Medial Solutions, Erlangen, Germany). Imaging included a true whole-body scan with extended field of view (slice thickness (SL) 2 mm), head and neck (SL 0.6 mm), thorax and abdomen (SL 1 mm) with soft tissue and bone window/lung window with respectively a soft and hard kernel reconstruction. Multiplanar and 3-dimensional reformations were performed at a multimodality workplace (LEONARDO, SynGo, Siemens Medical Solutions), and a final read-out was performed on a PACS station (Picture and Archiving Communication System, Sectra, Linköping, Sweden) by a board-certified radiologist with experience in forensic imaging. The forensic pathologists were provided with the pmCT findings to receive information that was essential to the case.
Shot number 2: The right ramus mandible exhibited an entry wound with small bony fragments that were medial and lateral to the lower jaw and an adjacent fracture of the processus angularis (Fig. 2A). The corresponding exit wound and surrounding hematoma were located on the contralateral lower neck (Fig. 3). Ascending thoracocervical soft tissue emphysema was also noted on the left neck. A comminuted fracture of the right part of the second cervical vertebra with destruction of the right canalis vertebralis and a fracture of the vertebral arch of the third cervical vertebra were detected within the bullet path on the left (Fig. 3). This finding was indicative of vertebral artery injury. Shot number 3: The head scan revealed a right-sided occipitoparietal galeal hematoma with an inward bevel that was adjacent to the right parietal entry wound near the vertex and scattered osseous fragments along the bullet path that struck the ipsilateral petrous bone at the internal meatus acusticus. The projectile was lodged in the spinal canal at the third cervical vertebra (Fig. 2B and Fig. 4). Only sparse hemorrhages were observed along the parenchymal bullet track with concomitant traumatic subarachnoid hemorrhage.
5.2. Thorax and abdomen 5. Imaging findings 5.1. Head and neck Shot number 1: The perforating shot in the right earlobe and the retroauricular grazing shot that were observed on an external inspection were not detectable by pmCT.
The thorax demonstrated a vast bilateral pneumothorax and the mediastinum showed soft tissue emphysema. A malpositioning of the endotracheal tube into the right main bronchus was detected (Fig. 5). No diaphragm or airway ruptures were detected. A horizontal sternum fracture and serial buckle-rib fractures were observed on the left [15]. No gas embolism was detected.
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Fig. 2. (A) View of the right side showing a 3D-VRT (Volume Rendering Technique) of the CT data. (B) View of the right skull after virtual sagittal transection of the left hemicranium using 3D-VRT. Note the steep angle of the right parietal entry wound of the penetrating gunshot near the vertex with scattered osseous fragments along the bullet path (according to the autopsy photograph of Fig. 3E). The bullet struck the right petrous bone at the level of the internal meatus acusticus, and the projectile lodged in the spinal canal at the third cervical vertebra (B, white arrow). Image A of the right ramus mandible shows the entry wound (white arrow) with small bony fragments medial and lateral to the lower jaw and the adjacent fracture of the processus angularis.
The abdomen contained a distended air-filled stomach and a duodenum with slight pneumoperitoneum. No other pathologies or signs of decomposition were observed on pmCT.
6. Autopsy An experienced resident and a board-certified forensic pathologist performed the autopsy. A standard autopsy of the three body cavities (skull, thorax and abdomen) was performed, and the neck was dissected. Histology did not reveal any additional relevant pathology. 6.1. Head and neck Shot number 1: Autopsy revealed no additional information. Shot number 2: Neck dissection revealed left-sided hemorrhage of the superficial to deep tissue layers. The bullet path from the right mandibular entry wound to the exit wound on the left neck were probed (Figs. 1 and 3). The vertebral fractures and the vertebral artery at the craniocervical junction were not dissected. The retrieved, almost pristine bullet was consistent with a 6.35-mm pistol (Fig. 4F). Shot number 3: Autopsy showed an occipitoparietal galeal hematoma with a non-adaptable soft tissue defect that was consistent with an entrance wound (Fig. 4). An underlying round (5 mm) osseous defect with an inward bevel and a transection of the dura mater (1 cm) analogous to the bone defect were observed. Subarachnoid bleeding and acute brain edema were detected. The right petrous bone presented with fracture but was not opened during autopsy. The intracranial vessels exhibited no pathology.
6.2. Thorax and abdomen Autopsy confirmed a bilateral pneumothorax and revealed additional hemorrhagic, fissural ventral serial rib fractures in the left abdomen. Pneumoperitoneum was not detected.
7. Discussion Imaging revealed findings that were sufficient to establish the possible shot sequence necessarily corroborated by a complete police and forensic analysis involving eyewitness statements. Eyewitnesses reported three shots, and this was confirmed using external inspection and pmCT; these shots were also validated using the gold standard, forensic autopsy and police reports. Postmortem CT revealed a lodged projectile within the spinal canal at the third cervical vertebral body from the head shot wound (shot number 3), which precisely crossed the actual bullet path of the right transmandibular shot (shot number 2) with the corresponding exit wound on the left neck. However, there is the possibility that the projectile may have come to rest on its own at that level prior to the shot through the mandible/neck, or it may have come to rest slightly higher and then slipped further down after the shot through the neck taking into account potential migration of the projectile. Still, imaging corresponding to autopsy together with the eyewitness' report indicated that the head shot with the lodged projectile did occur after the transmandibular gunshot wound; otherwise, the projectile would have been displaced or destructed (Figs. 3 and 4). We hypothesized that the first shot was the perforating shot to the earlobe with its retroauricular grazing shot based on the eye-witness reports, external inspection and imaging. Neither soot nor powder stippling was observed at the right ear. The shooting direction and angle suggested that the victim was in an upright position and was approached from the front. Thereafter, the distance to the victim likely decreased further, and the transmandibular shot occurred at relatively close range (the second shot with powder stippling at the right cheek) with a descending bullet path, presumably while the victim was in an upright position. The third and final shot was to the high parietal region near the vertex at a steep angle. The victim was approached from the right side, which drives the assumption that the victim had fallen and was shot while in a prone position. Nevertheless, homicidal shootings are complex events with the relationship between the shooter and victim often in continual flux. The trajectory of a wound through the body only fixes the relationship of the gun to the victim at the time of the shot.
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Fig. 3. (A) Angulated coronal multiplanar reconstruction of the skull and vertebral spine in the osseous window. The white arrows indicate the shooting vector and the descending bullet path. Note the fracture of the right ramus mandible from the osseous bullet entry with small bony fragments that are medial and lateral to the lower jaw. The bullet channel exactly crosses the lodged projectile within the spinal canal at the third cervical vertebral body. (B) Autopsy photograph. The bullet path was probed to visualize the bullet path after the lodged bullet was retrieved. (C–F) Axial plane in the bone kernel. Depiction of the posterior descending bullet path of the transmandibular shot on the right side (the white arrow indicates the shooting direction). (C) Level of the right mandible with the perforating shot. Note the soft tissue emphysema and the potential lesion in the pharynx adjacent to the bullet path. (D) Level of the second cervical vertebra with the destruction of the right canalis vertebralis. (E) Level of the third cervical vertebra with the corresponding fracture in the vertebral arch on the left side. The bullet lodged in the myelin and crossed precisely the actual bullet path of the right transmandibular shot with the corresponding exit wound on the left neck. (F) Depiction of the exit wound at the left lower neck with a thickening of the musculature due to hemorrhage and subcutaneous bleeding. The tip of the arrow points to the cutaneous exit wound.
Fig. 4. (A) Sagittal multiplanar reconstruction of the skull and vertebral spine in the osseous window. Postmortem CT depicts the intact projectile lodged within the spinal canal at the third cervical vertebral body. Note the galeal hematoma at the site of the vertex near the parietal gunshot wound with typical inward beveling (red line) of the entry shot wound (white arrow). (B) Coronal multiplanar reconstruction of the skull and vertebral spine in the osseous window. Note the distinct inward beveling with the inwardly displaced osseous fragment corresponding to (A, B) and (E). (C) Autopsy photograph of the head gunshot entry wound. (D) Osseous defect and galeal hematoma of the entry wound. (E) Internal view of the calvarium with inside beveling and a larger displaced osseous fragment. (F) The bullet that was retrieved from the spinal canal was consistent with a 6.35-mm pistol.
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dislocated, and this damage likely did not cause the gas accumulation. No other airway injury or diaphragm lesion was observed. Imaging provided additional information by revealing the malpositioned endotracheal tube, the precise fracture patterns and the potential injury to the right vertebral artery due to the adjacent fracture. In addition, pmCT of the case allows for a permanent record to be stored and can be re-evaluated at any point of time or shared for counter-expertise. This case report clearly illustrates that pmCT enhanced the forensic investigation and facilitates dissection of complex regions like the neck and may aid in determination of a possible chronology of successive shooting. Therefore, pmCT should be routinely used in the forensic investigation of cases to yield as much information as possible and provide a superior state-of-the-art examination in forensic pathology [18].
Discloser Nothing to disclose. References
Fig. 5. Coronal maximum intensity projection of the thorax in the pulmonary window. Note the displaced endotracheal tube, the vast bilateral pneumothorax and the emphysema along the thoracocervical soft tissue. Also note the mediastinum and slight pneumoperitoneum. The air distention of the stomach is due to ventilation prior to intubation.
However, it does not fix the relationship of the gun to the shooter or of the shooter and the victim to the external environment. Certainly, the range of fire does not necessarily decrease with subsequent gunshots. The gunshot wound of the ear could have occurred at any point during the sequence but was witnessed by several people as the first shot. The third shot lodged in the myelin of the third vertebral body, and this was consistent with a target that led to the immediate incapacity of the victim. Therefore, the cause of death was stated to be gunshot wounds of the head that initiated a fatal sequence of events. An external inspection by a radiologist and a forensic pathologist was crucial, as the perforating shot with its retroauricular grazing shot could not be assessed using merely pmCT. Autopsy was clearly superior for detailing the brain edema, and this was difficult to assess using pmCT due to poor soft tissue differentiation but may be detectable on postmortem MR [16,17]. However, pmCT was superior in revealing the sternal fracture, the precise location of the lodged projectile, the extent of soft tissue emphysema, pneumothorax, mediastinum and peritoneum and the lack of fatal gas embolism. The vast pneumothorax with extensive emphysema that was observed on both autopsy and pmCT was explicable by the assisted ventilation that was administered prior to intubation during resuscitation attempts, the potential pharyngeal lesion that was due to the transmandibular shot, gas accumulation within the tissue and the concomitant tension pneumothorax (Fig. 5). The thoracic cage fractures were not
[1] G.N. Rutty, Are autopsies necessary? The role of computed tomography as a possible alternative to invasive autopsies, Rechtsmed 17 (2007) 21–28. [2] K. Poulsen, J. Simonsen, Computed tomography as routine in connection with medico-legal autopsies, Forensic Science International 171 (2007) 190–197. [3] C. O′Donnell, A. Rotman, S. Collett, N. Woodford, Current status of routine postmortem CT in Melbourne, Australia, Forensic Science, Medicine and Pathology 3 (2007) 226–232. [4] A.D. Levy, H.T. Harcke, C.T. Mallak, Essentials of Forensic Imaging: A Text-Atlas, CRC Press, Boca Raton, FL, 2011. [5] S. Ross, D. Spendlove, S. Bolliger, et al., Postmortem whole-body CT angiography: evaluation of two contrast media solutions, American Journalism Review 190 (5) (2008) 1380–1389. [6] R. Dirnhofer, C. Jackowski, P. Vock, K. Potter, M.J. Thali, VIRTOPSY: minimally invasive, imaging-guided virtual autopsy, Radio Graphics 26 (2006) 1305–1333. [7] M.J. Thali, C. Jackowski, L. Oesterhelweg, S.G. Ross, R. Dirnhofer, VIRTOPSY—the Swiss virtual autopsy approach, Legal Medicine 9 (2007) 100–104. [8] M.J. Thali, W. Schweitzer, K. Yen, et al., The 60-second digital autopsy—fullbody examination of a gunshot victim by multislice computed tomography, American Journal of Forensic Medicine and Pathology 24 (2003) 1. [9] M.J. Thali, K. Yen, P. Vock, et al., Image-guided virtual autopsy findings of gunshot victims performed with multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) and subsequent correlation between radiology and autopsy findings, Forensic Science International 138 (2003) 8–16. [10] H.T. Harcke, A.D. Levy, J.M. Getz, S.R. Robinson, MDCT analysis of projectile injury in forensic investigation, American Journalism Review 190 (2008) 106–111. [11] A.J. Jeffery, G.N. Rutty, C. Robinson, B. Morgan, Computed tomography of projectile injuries, Clinical Radiology 63 (2008) 1160–1166. [12] H.T. Harcke, A.D. Levy, R.M. Abbott, et al., Digital Radiographs (DR) vs Multidetector Computed Tomography (MDCT) in high-velocity gunshotwound victims, American Journal of Forensic Medicine and Pathology 28 (2007) 13–19. [13] A.D. Levy, R.M. Abbott, C.T. Mallak, et al., Virtual Autopsy: preliminary experience in high-velocity gunshot wound victims, Radiology 240 (2006) 2. [14] C. von See, K-H. Bormann, P. Schumann, F. Goetz, N-C. Gellrich, M. Rücker, Forensic imaging of projectiles using cone-beam computed tomography, Forensic Science International 190 (2009) 38–41. [15] K. Yang, M. Lynch, M. O′Donnell, Buckle rib fracture: an artifact following cardio-pulmonary resuscitation detected on postmortem CT, Legal Medicine (Tokyo) 13 (5) (2011) 233–239. [16] K. Yen, K-O. Lövblad, E. Scheurer, et al., Post-mortem forensic neuroimaging: Correlation of MSCT and MRI findings with autopsy results, Forensic Science International 173 (2007) 21–35. [17] P.M. Flach, S.G. Ross, A. Christe, M.J. Thali, Clinical and forensic radiology are not the Same, in: MJ Thali, MD Viner, BG Brogdon (Eds.), Brogdon’s Forensic Radiology, 2nd Edition,Fla CRC Press, Boca Raton, 2010, pp. 409–440. [18] C. O′Donnell, N. Woodford, Post-mortem radiology. A new sub-speciality? Clinical Radiology 63 (2008) 1189–1194.
Contents lists available at SciVerse ScienceDirect
Journal of Forensic Radiology and Imaging journal homepage: www.elsevier.com/locate/jofri
Case report
Shot sequence detection aided by postmortem computed tomography in a case of homicide Patricia M Flach a,b,n, Garyfalia Ampanozi a, Tanja Germerott c, Steffen G Ross a, Astrid Krauskopf a, Michael J Thali a, Michael T Mund a a
Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland c Institute of Forensic Medicine, Medical School Hannover, Hannover, Germany b
ar t ic l e i nf o
a b s t r a c t
Article history: Received 1 November 2012 Received in revised form 21 March 2013 Accepted 22 March 2013
This study investigated the use of postmortem computed tomography (pmCT) in a homicide victim with three gunshots. This case report illustrates that pmCT enhances the forensic investigation and facilitates dissection of complex regions like the neck and may aid in the determination of a possible chronology of successive shooting. Postmortem imaging should be included as an established standard protocol in any state-of-the-art gunshot injury examination in forensic pathology, as this imaging method may provide more information than autopsy alone. & 2013 Elsevier Ltd. All rights reserved.
Keywords: Virtopsy Gun shot Homicide PmCT Postmortem Computed tomography Autopsy
1. Introduction The use of 2-dimensional radiography for gunshot wounds is well established in forensic medicine. However, the role of radiology in a forensic examination has expanded during the past decade to include postmortem computed tomography (pmCT), pmCT-angiography (pmCTA), image-guided biopsy and magnetic resonance imaging [1–5]. The virtual autopsy (“Virtopsy”) is particularly advantageous in gunshot victims, as pmCT is a non-invasive technique that aids in the detection and precise spatial localization of foreign bodies such as metallic fragments or projectiles and guides the forensic pathologist during bullet retrieval [6–8]. In addition, 3-dimensional pmCT can be used to document the bullet path(s) by depicting typical gunshot wound fracture patterns, discriminating osseous entry and exit wounds and evaluating any associated tissue damage prior to autopsy [9–14]. Additionally, the shooting direction, number and type of shots (e.g., penetrating, perforating, grazing, or self- or foreign forceinflicted), firing distance and an inference of the weapon and ammunition are of forensic interest. The investigation should also detect the source of immediate incapacitation and the manner and
n Correspondence to: Institute of Legal Medicine, Virtopsy, University of Zurich, Winterthurerstrasse 190/52, 8057 Zurich, Switzerland. Tel.: +41 44 635 5611; fax: +41 44 635 6851. E-mail address: patricia.fl[email protected] (P.M. Flach).
2212-4780/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jofri.2013.03.045
cause of death. This report of a homicide case delineates the feasibility of pmCT prior to autopsy to determine the precise anatomy and maybe even chronology of successive gunshots.
2. Case history A 55-year-old woman was shot by her husband three times in a public place and succumbed to her injuries at the crime scene.
3. External inspection The corpse presented with sparse livor mortis. Shot number 1: A position-dependent blood track was observed at the right ear with a cartilaginous and soft tissue burst of the right earlobe, which was consistent with a perforating shot. A retroauricular longitudinal abrasion was the result of a grazing shot. Shot number 2: Crepitation was detected in the right mandible with palpable soft tissue emphysema in the left midface, neck and thorax. An oval defect (5 mm) with an abraded appearance (1–4 mm) and powder stippling on the skin of the right mandible was compatible with an entry wound, and a larger
P.M. Flach et al. / Journal of Forensic Radiology and Imaging 1 (2013) 68–72
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Fig. 1. (A) View of the right side of the cheek. The image depicts an oval defect with an abraded appearance on the right mandible that is compatible with an entry wound. Note the hemorrhage at the right earlobe due to the perforating shot. (B) Magnified view of the entry wound of the gunshot. (C) View of the left side of the neck. Note the enlarged adaptable slit-like defect on the left distal neck, which is consistent with an exit wound. (D) Magnified view of the gunshot exit wound.
(1 cm), adaptable slit-like defect at the left distal neck was consistent with an exit wound (Fig. 1). Shot number 3: A “cracked pot” sound in the skull and right occipitoparietal galeal swelling with an oval (5 mm) non-adaptable soft tissue defect consistent with an entrance wound were detected. There was no other exit wound detectable. No additional relevant findings were observed. 4. Imaging The corpse received a full-body dual-source pmCT scan (SOMATOM Definition Flash, Siemens Medial Solutions, Erlangen, Germany). Imaging included a true whole-body scan with extended field of view (slice thickness (SL) 2 mm), head and neck (SL 0.6 mm), thorax and abdomen (SL 1 mm) with soft tissue and bone window/lung window with respectively a soft and hard kernel reconstruction. Multiplanar and 3-dimensional reformations were performed at a multimodality workplace (LEONARDO, SynGo, Siemens Medical Solutions), and a final read-out was performed on a PACS station (Picture and Archiving Communication System, Sectra, Linköping, Sweden) by a board-certified radiologist with experience in forensic imaging. The forensic pathologists were provided with the pmCT findings to receive information that was essential to the case.
Shot number 2: The right ramus mandible exhibited an entry wound with small bony fragments that were medial and lateral to the lower jaw and an adjacent fracture of the processus angularis (Fig. 2A). The corresponding exit wound and surrounding hematoma were located on the contralateral lower neck (Fig. 3). Ascending thoracocervical soft tissue emphysema was also noted on the left neck. A comminuted fracture of the right part of the second cervical vertebra with destruction of the right canalis vertebralis and a fracture of the vertebral arch of the third cervical vertebra were detected within the bullet path on the left (Fig. 3). This finding was indicative of vertebral artery injury. Shot number 3: The head scan revealed a right-sided occipitoparietal galeal hematoma with an inward bevel that was adjacent to the right parietal entry wound near the vertex and scattered osseous fragments along the bullet path that struck the ipsilateral petrous bone at the internal meatus acusticus. The projectile was lodged in the spinal canal at the third cervical vertebra (Fig. 2B and Fig. 4). Only sparse hemorrhages were observed along the parenchymal bullet track with concomitant traumatic subarachnoid hemorrhage.
5.2. Thorax and abdomen 5. Imaging findings 5.1. Head and neck Shot number 1: The perforating shot in the right earlobe and the retroauricular grazing shot that were observed on an external inspection were not detectable by pmCT.
The thorax demonstrated a vast bilateral pneumothorax and the mediastinum showed soft tissue emphysema. A malpositioning of the endotracheal tube into the right main bronchus was detected (Fig. 5). No diaphragm or airway ruptures were detected. A horizontal sternum fracture and serial buckle-rib fractures were observed on the left [15]. No gas embolism was detected.
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Fig. 2. (A) View of the right side showing a 3D-VRT (Volume Rendering Technique) of the CT data. (B) View of the right skull after virtual sagittal transection of the left hemicranium using 3D-VRT. Note the steep angle of the right parietal entry wound of the penetrating gunshot near the vertex with scattered osseous fragments along the bullet path (according to the autopsy photograph of Fig. 3E). The bullet struck the right petrous bone at the level of the internal meatus acusticus, and the projectile lodged in the spinal canal at the third cervical vertebra (B, white arrow). Image A of the right ramus mandible shows the entry wound (white arrow) with small bony fragments medial and lateral to the lower jaw and the adjacent fracture of the processus angularis.
The abdomen contained a distended air-filled stomach and a duodenum with slight pneumoperitoneum. No other pathologies or signs of decomposition were observed on pmCT.
6. Autopsy An experienced resident and a board-certified forensic pathologist performed the autopsy. A standard autopsy of the three body cavities (skull, thorax and abdomen) was performed, and the neck was dissected. Histology did not reveal any additional relevant pathology. 6.1. Head and neck Shot number 1: Autopsy revealed no additional information. Shot number 2: Neck dissection revealed left-sided hemorrhage of the superficial to deep tissue layers. The bullet path from the right mandibular entry wound to the exit wound on the left neck were probed (Figs. 1 and 3). The vertebral fractures and the vertebral artery at the craniocervical junction were not dissected. The retrieved, almost pristine bullet was consistent with a 6.35-mm pistol (Fig. 4F). Shot number 3: Autopsy showed an occipitoparietal galeal hematoma with a non-adaptable soft tissue defect that was consistent with an entrance wound (Fig. 4). An underlying round (5 mm) osseous defect with an inward bevel and a transection of the dura mater (1 cm) analogous to the bone defect were observed. Subarachnoid bleeding and acute brain edema were detected. The right petrous bone presented with fracture but was not opened during autopsy. The intracranial vessels exhibited no pathology.
6.2. Thorax and abdomen Autopsy confirmed a bilateral pneumothorax and revealed additional hemorrhagic, fissural ventral serial rib fractures in the left abdomen. Pneumoperitoneum was not detected.
7. Discussion Imaging revealed findings that were sufficient to establish the possible shot sequence necessarily corroborated by a complete police and forensic analysis involving eyewitness statements. Eyewitnesses reported three shots, and this was confirmed using external inspection and pmCT; these shots were also validated using the gold standard, forensic autopsy and police reports. Postmortem CT revealed a lodged projectile within the spinal canal at the third cervical vertebral body from the head shot wound (shot number 3), which precisely crossed the actual bullet path of the right transmandibular shot (shot number 2) with the corresponding exit wound on the left neck. However, there is the possibility that the projectile may have come to rest on its own at that level prior to the shot through the mandible/neck, or it may have come to rest slightly higher and then slipped further down after the shot through the neck taking into account potential migration of the projectile. Still, imaging corresponding to autopsy together with the eyewitness' report indicated that the head shot with the lodged projectile did occur after the transmandibular gunshot wound; otherwise, the projectile would have been displaced or destructed (Figs. 3 and 4). We hypothesized that the first shot was the perforating shot to the earlobe with its retroauricular grazing shot based on the eye-witness reports, external inspection and imaging. Neither soot nor powder stippling was observed at the right ear. The shooting direction and angle suggested that the victim was in an upright position and was approached from the front. Thereafter, the distance to the victim likely decreased further, and the transmandibular shot occurred at relatively close range (the second shot with powder stippling at the right cheek) with a descending bullet path, presumably while the victim was in an upright position. The third and final shot was to the high parietal region near the vertex at a steep angle. The victim was approached from the right side, which drives the assumption that the victim had fallen and was shot while in a prone position. Nevertheless, homicidal shootings are complex events with the relationship between the shooter and victim often in continual flux. The trajectory of a wound through the body only fixes the relationship of the gun to the victim at the time of the shot.
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Fig. 3. (A) Angulated coronal multiplanar reconstruction of the skull and vertebral spine in the osseous window. The white arrows indicate the shooting vector and the descending bullet path. Note the fracture of the right ramus mandible from the osseous bullet entry with small bony fragments that are medial and lateral to the lower jaw. The bullet channel exactly crosses the lodged projectile within the spinal canal at the third cervical vertebral body. (B) Autopsy photograph. The bullet path was probed to visualize the bullet path after the lodged bullet was retrieved. (C–F) Axial plane in the bone kernel. Depiction of the posterior descending bullet path of the transmandibular shot on the right side (the white arrow indicates the shooting direction). (C) Level of the right mandible with the perforating shot. Note the soft tissue emphysema and the potential lesion in the pharynx adjacent to the bullet path. (D) Level of the second cervical vertebra with the destruction of the right canalis vertebralis. (E) Level of the third cervical vertebra with the corresponding fracture in the vertebral arch on the left side. The bullet lodged in the myelin and crossed precisely the actual bullet path of the right transmandibular shot with the corresponding exit wound on the left neck. (F) Depiction of the exit wound at the left lower neck with a thickening of the musculature due to hemorrhage and subcutaneous bleeding. The tip of the arrow points to the cutaneous exit wound.
Fig. 4. (A) Sagittal multiplanar reconstruction of the skull and vertebral spine in the osseous window. Postmortem CT depicts the intact projectile lodged within the spinal canal at the third cervical vertebral body. Note the galeal hematoma at the site of the vertex near the parietal gunshot wound with typical inward beveling (red line) of the entry shot wound (white arrow). (B) Coronal multiplanar reconstruction of the skull and vertebral spine in the osseous window. Note the distinct inward beveling with the inwardly displaced osseous fragment corresponding to (A, B) and (E). (C) Autopsy photograph of the head gunshot entry wound. (D) Osseous defect and galeal hematoma of the entry wound. (E) Internal view of the calvarium with inside beveling and a larger displaced osseous fragment. (F) The bullet that was retrieved from the spinal canal was consistent with a 6.35-mm pistol.
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dislocated, and this damage likely did not cause the gas accumulation. No other airway injury or diaphragm lesion was observed. Imaging provided additional information by revealing the malpositioned endotracheal tube, the precise fracture patterns and the potential injury to the right vertebral artery due to the adjacent fracture. In addition, pmCT of the case allows for a permanent record to be stored and can be re-evaluated at any point of time or shared for counter-expertise. This case report clearly illustrates that pmCT enhanced the forensic investigation and facilitates dissection of complex regions like the neck and may aid in determination of a possible chronology of successive shooting. Therefore, pmCT should be routinely used in the forensic investigation of cases to yield as much information as possible and provide a superior state-of-the-art examination in forensic pathology [18].
Discloser Nothing to disclose. References
Fig. 5. Coronal maximum intensity projection of the thorax in the pulmonary window. Note the displaced endotracheal tube, the vast bilateral pneumothorax and the emphysema along the thoracocervical soft tissue. Also note the mediastinum and slight pneumoperitoneum. The air distention of the stomach is due to ventilation prior to intubation.
However, it does not fix the relationship of the gun to the shooter or of the shooter and the victim to the external environment. Certainly, the range of fire does not necessarily decrease with subsequent gunshots. The gunshot wound of the ear could have occurred at any point during the sequence but was witnessed by several people as the first shot. The third shot lodged in the myelin of the third vertebral body, and this was consistent with a target that led to the immediate incapacity of the victim. Therefore, the cause of death was stated to be gunshot wounds of the head that initiated a fatal sequence of events. An external inspection by a radiologist and a forensic pathologist was crucial, as the perforating shot with its retroauricular grazing shot could not be assessed using merely pmCT. Autopsy was clearly superior for detailing the brain edema, and this was difficult to assess using pmCT due to poor soft tissue differentiation but may be detectable on postmortem MR [16,17]. However, pmCT was superior in revealing the sternal fracture, the precise location of the lodged projectile, the extent of soft tissue emphysema, pneumothorax, mediastinum and peritoneum and the lack of fatal gas embolism. The vast pneumothorax with extensive emphysema that was observed on both autopsy and pmCT was explicable by the assisted ventilation that was administered prior to intubation during resuscitation attempts, the potential pharyngeal lesion that was due to the transmandibular shot, gas accumulation within the tissue and the concomitant tension pneumothorax (Fig. 5). The thoracic cage fractures were not
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