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Forensic assessment of survived strangulation
Forensic Science International 153 (2005) 202–207 www.elsevier.com/locate/forsciint
Forensic assessment of survived strangulation T. Plattner*, S. Bolliger, U. Zollinger Institute of Forensic Medicine, University of Berne, Bu¨hlstrasse 20, 3012 Berne, Switzerland Received 5 March 2003; accepted 3 September 2004 Available online 5 November 2004
Abstract By a retrospective analysis of all survived strangulation cases examined at the Institute of Forensic Medicine of Berne, Switzerland between 1987 and 2002, the authors tried to find out, if findings and symptoms of victims could be related to the fierceness of the assault and the mode of strangulation and if general evaluation criteria could be established on the basis of objective findings. One hundred and thirty-four survived strangulation cases were analysed on the basis of written reports, photographies and schematical sketches. Findings and symptoms reflected the fierceness of the assault in 71% of all cases by displaying a continuum of findings from minor injuries to severe traumatisation. This applied especially for cases of manual strangulation while other modes of strangulation resulted in different constellations of findings. As a result of this study, the authors deem the following classification of three degrees of severity as practical on condition that a complete forensic medical examination was performed upon the surviving victim shortly after the incident of strangulation: Light strangulation, confined to skin abrasions and/or reddening of the skin of the neck. Moderate strangulation, defined as bruising to, and/or bleeding from the neck, and/or damage to deeper soft tissues or the larynx, as exhibited by the symptoms of sore throat, difficulty in swallowing, and hoarseness. Severe, life-threatening strangulation if the victim presents petechial bleedings as a result of venous congestion with or without accompanying loss of consciousness. # 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Survived strangulation; Clinical forensic medicine; Assessment of survived strangulation; Causes of death in strangulation
1. Introduction The examination of persons who were assaulted by strangulation is a common task for any physician working in the field of clinical forensic medicine. The great difficulty in such cases lies in the interpretation of findings in reference to the intensity and the duration of the assault and, ultimately, the threat it represented for the victim’s life [1]. The consequence of all forms of strangulation (manual strangulation, throttling, hanging) is a pressure on the air * Corresponding author. Tel.: +41 31 631 84 11; fax: +41 31 631 38 33. E-mail address: [email protected] (T. Plattner).
passages, the blood vessels and the nervous structures of the neck [2,3]. Despite the fact that these three possible damaging mechanisms have been described by Langreuter [3] in the late 19th century, the exact pathophysiological pathway, which ultimately causes death in strangulation, is not completely known yet [4]. There is no doubt among forensic pathologists, that obstruction of the blood vessels must be the main factor, while narrowing of the airways most probably plays a minor role [2,5–7]. On the other hand, obstruction of cerebral bloodflow cannot be regarded as the sole responsible pathophysiological process [4]. In that case, various degrees of hypoxic cerebral damage depending on the duration of hypoxia would occur. Cases of sustaining neurological impairment or delayed death after strangulation
0379-0738/$ – see front matter # 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.forsciint.2004.09.106
T. Plattner et al. / Forensic Science International 153 (2005) 202–207
are however rarely reported [4,8–14]. Most of the victims either die or survive without consequential brain damage. A fact that has been called ‘‘the all or nothing law of strangulation’’ by Jacob [15]. The role of the cardiac reflex by pressure on nervous structures in the neck (vagal nerve and glomus caroticum) in strangulation is a recurrent subject of controversial discussions among experts [2,16–23]. Strauch et al. [24] offer an overview of findings and symptoms of living strangulation victims based on a study on 81 cases of survived strangulation. Strangulation victims may show superficial skin lesions, signs of soft tissue traumatism, laryngeal trauma, congestive petechiae on facial skin, conjunctivae and buccal mucosa and report signs of cerebral hypoxia. Superficial findings on the skin of the victim alone can occur in cases of mild trauma to the neck [1,25] while injury of soft tissue, represented by hematomas, swelling and evidence of affection of pharynx and larynx reflect a more intense traumatisation [1]. In strangulation petechiae on facial skin and conjunctivae are the result of a congestion by persistence of arterial and occlusion of venous bloodflow and rupture of capillaries in the skin [2,25–27]. Various statements on the time of venous occlusion required to produce petechiae are to be found in the literature. According to Bschor [28] 10–20 s would suffice. Jarosch [29] on the other hand claims, that it would require several minutes. According to Anscombe and Knight [4,5] a minimum time of 15–30 s would be required to give rise to petechiae in the eyelids. It must be considered, that a manual strangulation is a highly dynamic process. Any conscious and unimpaired adult victim would struggle in defence which would force the perpetrator to reduce his grip and to seize his victim over and over. All things considered, the presence of petechiae speaking for a probable minimum period of 10 s of uninterrupted venous compression, must be regarded as a strong indicator for a long and fierce assault [30]. A high evidential value for the severity of neck compression should thus be attributed to petechiae in the conjunctivae, mucosal surfaces and facial skin [24,25]. This is supported by the fact, that petechiae are virtually always present in cases of fatal manual and ligature strangulation [1,2,24,25,28]. By a retrospective analysis of all cases of survived strangulation of the Institute of Forensic Medicine of Bern, Switzerland between 1987 and 2002 the authors tried to find out if findings and symptoms could be related to the fierceness of the assault and if evaluation criteria could be established on the basis of objective findings.
2. Methods and material All cases of survived manual and ligature strangulation examined at the Institute of Forensic Medicine of Bern, Switzerland between 1987 and 2002 were analysed on the basis of written reports, police interrogation protocols, photographs and schematical sketches. Personal data of
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the victims and suspects, their relationships, detailed modes of strangulations as reported by the victims, findings and symptoms at the time of examination and during the assault were evaluated. Excluded were all forms of self inflicted strangulation as well as survived hanging. Findings and symptoms were divided into four classes. Superficial findings, such as erythema, abrasions and intracutaneous hemorrhages were attributed to class I. Findings due to soft tissue traumatisation (hematomas, swelling and painful palpation) as well as signs of affection of pharyngeal and laryngeal structures (sore throat, impairment of speech, hoarseness) were attributed to class II. Petechial hemorrhages were attributed to class III and findings related to neurologic impairment (loss of consciousness, loss of urine) were attributed to class IV respectively. Each case was analysed according to findings, their extent and combination of appearance.
3. Results A total of 134 cases of survived strangulation were included in the study. One hundred and ten (82%) cases were cases of manual strangulation. Twenty-one (16%) victims were attacked by ligature strangulation while in three (2%) cases manual and ligature strangulation were combined. Fig. 1 shows the age and gender distribution of the victims. In 4 (3%) cases the victim was a child, the remaining 130 (97%) victims being adults. Most victims (32%) were between 20 and 30 years of age. Twenty (15%) of the victims were males, 114 (85%) were females. In 112 cases (83%) the victim was female and the suspect was male. All male victims were assaulted by men and in two cases victim and suspect were females. In 47 (35%) cases the strangulation was inflicted during a rape or a rape attempt. In seven cases no symptoms were described by the victim and no findings could be observed at the forensic examination. During the assault 27 (20%) of all victims reported having had dyspnea. Thirteen (10%) described that they ‘‘nearly’’ fainted whereas 15 (11%) reported having lost consciousness completely. Four (3%) of the victims claimed that they had lost urine during the assault. Fig. 2 gives an overview on all findings that were detectable at the time of examination. In 29 (21%) of all cases petechial hemorrhages were documented. Only in three of these cases petechiae were not seen in the conjunctivae but in other sites (buccal mucosa, areas of skin around the eyes). Table 1 shows a classification of all cases by findings and symptoms. The majority of cases showed superficial skin lesion and injury of soft tissue, pharynx and larynx. Ninetyfive cases (71%) showed a continuum of findings from superficial skin lesions to petechiae and signs of cerebral impairment. All cases in the study with extensive petechiae showed all other symptoms and findings supporting the assumption, that a fierce strangulation took place. In nine
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T. Plattner et al. / Forensic Science International 153 (2005) 202–207
Fig. 1. Age and gender of victims.
cases, where the victims suffered a loss of consciousness and/or loss of urine, injuries of the neck as well as petechiae were documented. In six cases loss of consciousness was not associated with petechiae. Four of these victims however suffered a non-negligible trauma of the head which could explain that unconsciousness was not due to strangulation but to a cerebral concussion. Based on the forensic reports no clinical symptoms of neurological impairment or serious traumatism of the organs of the neck after the incident were observed. In none of the cases a clinical examination of the victim was, however, carried out.
4. Discussion No one would deny that strangulation is a dangerous form of assault. It would however be wrong to consider any grasp at the neck as life threatening. The threat for the victims life is greater with increasing intensity and duration of the assault. But when exactly does a pressure on the neck become a danger to the life of the victim? How much time and force is necessary? How can the intensity of the assault be proven by findings on the living victim after the incident? These are the essential questions in survived strangulation cases, to which the forensic expert has to answer in the court
Fig. 2. Findings on victims.
T. Plattner et al. / Forensic Science International 153 (2005) 202–207 Table 1 Frequency of groups of findings and symptoms and their combination Number of cases
Findings I
II
III
IV
7 33 44 9 9
No findings and symptoms X X X X X X X X X
X
17 6 4 3 1 1
X X X
X
X X X
X X X X
The cases on gray background representing a continuum of findings related to the intensity of the assault. I: superficial skin lesions (hyperemia, abrasions and intracutaneous bleeding); II: signs of soft tissue lesions or lesions of pharynx and larynx (hematomas, swelling, painful palpation, hoarseness, sore throat, radiologic demonstration of lesion such as fractures of hyoid bone and thyroid cartilage); III: petechial bleedings on conjunctivae, mucosal surfaces and facial skin; IV: signs of cerebral hypoxia (loss of consciousness, loss of urine, etc.).
room. The Swiss penal code for instance discerns between ‘‘simple-’’ and ‘‘severe bodily harm’’ in cases where a victim was injured and ‘‘endangerment of life’’ for potential lifethreatening situations without injury. In both ‘‘severe bodily harm’’ as well as ‘‘endangerment of life’’ – which are sanctioned by a considerably higher penalty than ‘‘simple bodily harm’’ – the main criterion is, that the victim was in an immediate life-threatening situation. ‘‘Endangerment of life’’ was the verdict by the Swiss Federal Court in a case of strangulation [31]. In this case the life-threatening character of the assault was based on victims statements on the duration of the attack and the presence of local abrasions and erythema on the skin. The forensic expert concluded in his statement, that the long duration of neck compression in this case would be associated with a high probability of a reflex cardiac death. The juridical qualification of the assault, the verdict and the degree of penalty can thus critically depend on the statement of the forensic expert as this case demonstrates. There are however no generally accepted evaluation criteria; this gives rise to an inconsistent assessment by forensic experts based on personal experience and opinion. An overview of all cases of survived strangulation at the Institute of Forensic Medicine of Bern, Switzerland between 1987 and 2002 has shown, that some experts would consider any grasp on the neck as potentially life threatening while others demand the presence of petechiae and/or unconsciousness as proof that the victim was in immediate danger to life. It has been shown in previous studies, that any judgement of intensity and duration of the strangulation by the injuries
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on the victim may be difficult and that different modes of strangulation are characterized by typical injuries [1,24,25]. This is supported by the results of our study. With reference to incidence and extent of findings and symptoms the results of our study are comparable to those by Strauch et al. [24]. A classification of all cases by the findings, as offered in Table 1, showed that a continuum of findings from superficial lesions to soft tissue traumatism and lesions of pharyngeal and laryngeal structures and signs of venous congestion and impaired cerebral functions were observed in the majority of cases (95 cases representing 71% of all cases). In most of these cases, manual strangulation on an uncovered neck (i.e. not protected by garment) took place. We concluded that the presence of superficial findings alone would speak for a relatively mild traumatisation and that with an increase of fierceness they would be combined with signs of soft tissue injury and injuries of pharynx and larynx as well as congestive petechiae and loss of consciousness in severe strangulation. In the remaining 37% of all cases, where an incontinuous pattern of findings was documented, the intensity of strangulation was difficult to judge. A thorough analysis of these cases showed, that the circumstances of the case, the mode of strangulation, the unspecificity of findings, the lapse of time between incident and examination, which can lead to disappearance of certain superficial findings and petechial hemorrhages [26], should be considered in each strangulation case. Ligature strangulation, especially when a broad and soft strangling object like a bath towel had been used, may show a lack of superficial lesions but can affect soft tissue (two cases in this study). The same can be stated for cases where the victim was strangled from behind by the suspects forearm (neck hold, ‘‘carotid sleeper’’ [32,33]) which was encountered in four cases. Petechiae should be combined with other strangulation findings and symptoms (class I, II, and IV findings) in order to be used as indicator for an intense assault. In cases with minor petechiae and no other signs of violent neck compression it should be considered, that they are not specific and may have other causes not related to strangulation [2,19,28,34–36]. On the other hand, the lack of positive signs of congestion at the time of examination may not exclude a severe strangulation in every case. Petechiae may vanish after 1–3 days after the incident [24,37]. It has been shown that a neck hold can result in a complete occlusion of carotid and vertebral arteriae [32,33,38]. In cases where a strangulation with the forearm (neck hold, ‘‘Carotid sleeper’’) took place, the rare possibility of occlusion of both venous and arterial blood vessels should therefore be considered [33]. Symptoms indicating an impaired cerebral function should be interpreted with caution because of their subjective nature. Loss of consciousness and/or incontinence should not be regarded as proof for a severe strangulation, if no other findings, namely petechiae, are present [24]. Other causes for loss of consciousness must be excluded
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[1,24]. If no symptoms of impaired cerebral function are reported but clear signs of congestion and other typical strangulation findings are observable, a severe and lifethreatening strangulation should not be excluded since, as previously discussed, congestive petechiae prove the high intensity and relatively long duration of the assault. Based on the results of this study and a review of the literature the authors propose the categorisation of survived strangulation in three degrees of severity based on objective findings on condition that a complete forensic medical examination was performed upon the surviving victim shortly (1–2 days) after the incident and the mode of strangulation is known: 1. Light strangulation Presence of class I findings at typical sites on the skin consistent with mode of strangulation (class I findings may lack in strangulation with the forearm and/or ligature strangulation with a broad and soft object). Moderate strangulation 2. Presence of class I findings at typical sites on the skin consistent with mode of strangulation (class I findings may lack in strangulation with the forearm and/or ligature strangulation with a broad and soft object) and class II findings. 3. Severe, life-threatening strangulation Presence of class I findings at typical sites on the skin consistent with mode of strangulation (class I findings may lack in strangulation with the forearm and/or ligature strangulation with a broad and soft object), class II findings and distinct class III findings with or without class IV findings. Class I findings. Superficial skin lesions (hyperemia, abrasions and intracutaneous bleeding). Class II findings. Signs of soft tissue lesions or lesions of pharynx and larynx (hematomas, swelling, painful palpation, hoarseness, sore throat, radiologic demonstration of lesion such as fractures of hyoid bone and thyroid cartilage). Class III findings. Petechial bleedings on conjunctivae, mucosal surfaces and facial skin. Class IV findings. Signs of cerebral hypoxia (loss of consciousness, loss of urine, etc.). The authors are aware that any categorisation of a very complex matter like strangulation is a simplification that may not live up to reality in particular cases. Each strangulation case should therefore be treated and assessed individually. This classification should be considered as a proposition in order to standardize the forensic assessment of survived strangulation. The value of this classification has yet to be proven in daily forensic routine and scrutinized by further prospective studies.
In addition to the forensic examination, a clinical examination and radiological imaging of the victim should be considered and recommended in any case of serious intensity of strangulation and evidence of relevant traumatism of the neck or other relevant injuries.
References [1] T. Ha¨rm, J. Rajs, Types of injuries and interrelated conditions of victims and assailants in attempted and homicidal strangulation, Forensic Sci. Int. 18 (2) (1981) 101–123. [2] D.J. Di Maio, V.J.M. Di Mao, Strangulation, in: D.J. Di Maio, V.J.M. Di Maio (Eds.), Forensic Pathology, 1st ed. CRC Press, New York, 1989, pp. 222–244. ¨ ber die mechanischen Verha¨ltnisse des Strangu[3] Langreuter, U lationstodes, Vjschr. Ger. Med. XLV (1896) 295–309. [4] A.M. Anscombe, B.H. Knight, Delayed death after pressure on the neck: possible causal mechanisms and implications for mode of death in manual strangulation discussed, Forensic Sci. Int. 78 (3) (1996) 193–197. [5] B. Knight, Fatal pressure on the neck, in: B. Knight (Ed.), Forensic Pathology, 2nd ed. Arnold, London, 1996, pp. 361– 391. [6] B. Brinkmann, E. Koops, F. Wischhusen, M. Kleiber, Compression of the neck and arterial obstruction, Z. Rechtsmed. 7 (1/2) (1981) 59–73. [7] E. Koops, K. Pu¨schel, F. Wischhusen, G. Fechner, B. Brinkmann, Zur Obstruktion der Halsarterien und der oberen Luftwege beim Wu¨rgen, Beitr. Ger. Med. 41 (1983) 315–321. [8] A. Hori, G. Hirose, S. Kataoka, K. Tsukada, K. Furui, H. Tonami, Delayed postanoxic encephalopathy after strangulation. Serial neuroradiological and neurochemical studies, Arch. Neurol. 4 (1991) 871–874. [9] E.C. Dooling, E.P. Richardson Jr., Delayed encephalopathy after strangling, Arch. Neurol. 33 (1976) 196–199. [10] E. Gamper, G. Stiefler, Klinisches Bild und anatomischer Befund nach Drosselung. Ein Beitrag zur o¨rtlichen Vulnerabilita¨t, Arch. Psychiatr. 106 (1938) 744–788. [11] H. Gerlach, Spa¨ttod nach Strangulation, Z. Ges. Ger. Med. 58 (1966) 50–54. [12] H. Maxeiner, Spa¨ttod nach Strangulation, Arch. Krim. 180 (1987) 161–171. ¨ ber Gehirnvera¨nderungen beim [13] W. Wu¨nscher, G. Mo¨bius, U Spa¨ttod nach Strangulation, Dtsch. Z. Ges. Ger. Med. 50 (1960) 235–243. [14] G. Zeitler, Ein Beitrag zur Kenntnis der Spa¨ttodesfa¨lle nach Erha¨ngen, Dtsch. Z. Ges. Ger. Med. 12 (1928) 360–391. [15] H. Jacob, Strangulation, in: O. Lubarsch, R. Ro¨ssle, F. Henke (Eds.), Handbuch der speziellen Pathologischen Anatomie und Histologie, in: W. Scholz (Ed.), Nervensystem, vol. 13, Springer, Berlin, 1957, pp. 1712–1731. [16] C. Henssge, Beweisthema todesursa¨chliche/lebensgefa¨hrliche Halskompression: Pathophysiologische Aspekte der Interpretation, in: B. Brinkmann, K. Pu¨schel (Eds.), Ersticken-Fortschritte in der Beweisfu¨hrung, Springer, Berlin, 1990, pp. 3–13. [17] A. Esser, Zur Frage des Erwu¨rgens ohne lokale anatomische Spuren beim Menschen und im Tierversuch (Ein Beitrag zur forensischen Bedeutung des Heringschen Carotissinusreflexes), Dtsch. Z. Ges. Ger. Med. 20 (1933) 361–375.
T. Plattner et al. / Forensic Science International 153 (2005) 202–207 [18] J. Kaiser, Anatomisch-physiologische Grundlagen und gerichtlich-medizinische Kasuistik des sogenannten Reflextodes bei mechanischen Reizen an Hals und weiblichem Genitale, Dissertation, University of Marburg, Marburg, 1967. [19] K. Meier, Zum Traumatischen Reflextod, Dissertation, University of Basel, Basel, 1986. [20] W.J. Kleemann, R. Urban, U. Graf, H.F. Tro¨ger, Kann ein Griff an den Hals zum reflektorischen Herztod fu¨hren? in: B. Brinkmann, K. Pu¨schel (Eds.), Ersticken-Fortschritte in der Beweisfu¨hrung, Springer, Berlin, 1990, pp. 15–19. [21] F. Strassmann, Tod durch Erwu¨rgen oder gewaltsames Anfassen des Halses, Vierteljahrschrift Ger. Med. XXXV (1908) 282–294. [22] J.S. Olbrycht, Beitra¨ge zur Lehre u¨ber den Tod durch Erha¨ngen, Z. Ger. Med. 54 (1963) 407–423. [23] L. Adelson, Possible neurological mechanisms responsible for sudden death with minimum anatomical findings, J. Forensic Med. 9 (1962) 10–16. [24] H. Strauch, E. Lignitz, G. Geserick, Obstruktive Asphyxie ¨ berlebenden, in: B. Brinkmann, K. (Wu¨rgen Drosseln) mit U Pu¨schel (Eds.), Ersticken-Fortschritte in der Beweisfu¨hrung, Springer, Berlin, 1990, pp. 248–255. [25] T. Kondo, P. Betz, W. Eisenmenger, Retrospective study on skin reddenings and petechiae in the eyelids and the conjunctivae in forensic physical examinations, Int. J. Leg. Med. 110 (1997) 204–207. [26] G. Geserick, U. Ka¨mpfe, Zur Bedeutung von Stauungsblutungen bei der gewaltsamen Asphyxie, in: B. Brinkmann, K. Pu¨schel (Eds.), Ersticken-Fortschritte in der Beweisfu¨hrung, Springer, Berlin, 1990, pp. 73–83. [27] F.A. Jaffe, Petechial hemorrhages. A review of pathogenesis, Am. J. Forensic Med. Pathol. 15 (3) (1994) 203–207.
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[28] F. Bschor, Diagnosis of congestive hemorrhage in the region of the head in strangulation and other causes of death, Beitr. Gerichtl. Med. 25 (1969) 146–152. [29] K. Jarosch, Experimentelle Untersuchungen u¨ber vaskula¨re und neurale Mechanismen bei gewaltsamer Erstickung, Habilitation, University of Salzburg, 1971. [30] H. Maxeiner, Zum Beweiswert von Kehlkopfverletzungen, Arch. Krim. 171 (1983) 33–44. [31] Swiss federal court decision, BGE 124 IV 53, 1998. [32] D.T. Reay, Death from law enforcement neck holds, Am. J. Forensic Med. Pathol. 3 (1982) 199–203. [33] W. Denk, K. Pu¨schel, J. Missliwetz, Befunde und a¨ussere Umsta¨nde bei Todesfa¨llen im Schwitzkasten, in: B. Brinkmann, K. Pu¨schel (Eds.), Ersticken-Fortschritte in der Beweisfu¨hrung, Springer, Berlin, 1990, pp. 189–196. [34] G. Adebahr, u¨ber die Wertigkeit von Zyanose und Petechien bei Gewalteinwirkung auf den Hals und gleichzeitig vorhandener erheblichen Ana¨mie, Z. Rechtsmed. 86 (1981) 123–128. [35] A. Pentila¨, P.J. Karhunen, V. Savolainen, J. Suvisaari, E. Tiainen, Weichteilblutungen im Halsbereich und Bindehautblutungen bei Todesfa¨llen durch innere Erkrankungen, Vergiftung oder Ertrinken, in: B. Brinkmann, K. Pu¨schel (Eds.), Ersticken-Fortschritte in der Beweisfu¨hrung, Springer, Berlin, 1990, pp. 96–101. [36] O. Prokop, R. Wabnitz, Vorkommen von Bindehautblutungen bei Lebenden und Toten dargestellt in 10 Tabellen, Z. Rechtsmed. 67 (1970) 249–257. [37] P. Betz, R. Penning, W. Keil, The detection of petechial hemorrhages of the conjunctivae in dependency on the postmortem interval, Forensic Sci. Int. 64 (1994) 61–67. [38] E.K. Kiowai, Deaths allegedly caused by the use of ‘‘choke holds’’ (shime-waza), J. Forensic Sci. 32 (2) (1987) 419–432.
Forensic assessment of survived strangulation T. Plattner*, S. Bolliger, U. Zollinger Institute of Forensic Medicine, University of Berne, Bu¨hlstrasse 20, 3012 Berne, Switzerland Received 5 March 2003; accepted 3 September 2004 Available online 5 November 2004
Abstract By a retrospective analysis of all survived strangulation cases examined at the Institute of Forensic Medicine of Berne, Switzerland between 1987 and 2002, the authors tried to find out, if findings and symptoms of victims could be related to the fierceness of the assault and the mode of strangulation and if general evaluation criteria could be established on the basis of objective findings. One hundred and thirty-four survived strangulation cases were analysed on the basis of written reports, photographies and schematical sketches. Findings and symptoms reflected the fierceness of the assault in 71% of all cases by displaying a continuum of findings from minor injuries to severe traumatisation. This applied especially for cases of manual strangulation while other modes of strangulation resulted in different constellations of findings. As a result of this study, the authors deem the following classification of three degrees of severity as practical on condition that a complete forensic medical examination was performed upon the surviving victim shortly after the incident of strangulation: Light strangulation, confined to skin abrasions and/or reddening of the skin of the neck. Moderate strangulation, defined as bruising to, and/or bleeding from the neck, and/or damage to deeper soft tissues or the larynx, as exhibited by the symptoms of sore throat, difficulty in swallowing, and hoarseness. Severe, life-threatening strangulation if the victim presents petechial bleedings as a result of venous congestion with or without accompanying loss of consciousness. # 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Survived strangulation; Clinical forensic medicine; Assessment of survived strangulation; Causes of death in strangulation
1. Introduction The examination of persons who were assaulted by strangulation is a common task for any physician working in the field of clinical forensic medicine. The great difficulty in such cases lies in the interpretation of findings in reference to the intensity and the duration of the assault and, ultimately, the threat it represented for the victim’s life [1]. The consequence of all forms of strangulation (manual strangulation, throttling, hanging) is a pressure on the air * Corresponding author. Tel.: +41 31 631 84 11; fax: +41 31 631 38 33. E-mail address: [email protected] (T. Plattner).
passages, the blood vessels and the nervous structures of the neck [2,3]. Despite the fact that these three possible damaging mechanisms have been described by Langreuter [3] in the late 19th century, the exact pathophysiological pathway, which ultimately causes death in strangulation, is not completely known yet [4]. There is no doubt among forensic pathologists, that obstruction of the blood vessels must be the main factor, while narrowing of the airways most probably plays a minor role [2,5–7]. On the other hand, obstruction of cerebral bloodflow cannot be regarded as the sole responsible pathophysiological process [4]. In that case, various degrees of hypoxic cerebral damage depending on the duration of hypoxia would occur. Cases of sustaining neurological impairment or delayed death after strangulation
0379-0738/$ – see front matter # 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.forsciint.2004.09.106
T. Plattner et al. / Forensic Science International 153 (2005) 202–207
are however rarely reported [4,8–14]. Most of the victims either die or survive without consequential brain damage. A fact that has been called ‘‘the all or nothing law of strangulation’’ by Jacob [15]. The role of the cardiac reflex by pressure on nervous structures in the neck (vagal nerve and glomus caroticum) in strangulation is a recurrent subject of controversial discussions among experts [2,16–23]. Strauch et al. [24] offer an overview of findings and symptoms of living strangulation victims based on a study on 81 cases of survived strangulation. Strangulation victims may show superficial skin lesions, signs of soft tissue traumatism, laryngeal trauma, congestive petechiae on facial skin, conjunctivae and buccal mucosa and report signs of cerebral hypoxia. Superficial findings on the skin of the victim alone can occur in cases of mild trauma to the neck [1,25] while injury of soft tissue, represented by hematomas, swelling and evidence of affection of pharynx and larynx reflect a more intense traumatisation [1]. In strangulation petechiae on facial skin and conjunctivae are the result of a congestion by persistence of arterial and occlusion of venous bloodflow and rupture of capillaries in the skin [2,25–27]. Various statements on the time of venous occlusion required to produce petechiae are to be found in the literature. According to Bschor [28] 10–20 s would suffice. Jarosch [29] on the other hand claims, that it would require several minutes. According to Anscombe and Knight [4,5] a minimum time of 15–30 s would be required to give rise to petechiae in the eyelids. It must be considered, that a manual strangulation is a highly dynamic process. Any conscious and unimpaired adult victim would struggle in defence which would force the perpetrator to reduce his grip and to seize his victim over and over. All things considered, the presence of petechiae speaking for a probable minimum period of 10 s of uninterrupted venous compression, must be regarded as a strong indicator for a long and fierce assault [30]. A high evidential value for the severity of neck compression should thus be attributed to petechiae in the conjunctivae, mucosal surfaces and facial skin [24,25]. This is supported by the fact, that petechiae are virtually always present in cases of fatal manual and ligature strangulation [1,2,24,25,28]. By a retrospective analysis of all cases of survived strangulation of the Institute of Forensic Medicine of Bern, Switzerland between 1987 and 2002 the authors tried to find out if findings and symptoms could be related to the fierceness of the assault and if evaluation criteria could be established on the basis of objective findings.
2. Methods and material All cases of survived manual and ligature strangulation examined at the Institute of Forensic Medicine of Bern, Switzerland between 1987 and 2002 were analysed on the basis of written reports, police interrogation protocols, photographs and schematical sketches. Personal data of
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the victims and suspects, their relationships, detailed modes of strangulations as reported by the victims, findings and symptoms at the time of examination and during the assault were evaluated. Excluded were all forms of self inflicted strangulation as well as survived hanging. Findings and symptoms were divided into four classes. Superficial findings, such as erythema, abrasions and intracutaneous hemorrhages were attributed to class I. Findings due to soft tissue traumatisation (hematomas, swelling and painful palpation) as well as signs of affection of pharyngeal and laryngeal structures (sore throat, impairment of speech, hoarseness) were attributed to class II. Petechial hemorrhages were attributed to class III and findings related to neurologic impairment (loss of consciousness, loss of urine) were attributed to class IV respectively. Each case was analysed according to findings, their extent and combination of appearance.
3. Results A total of 134 cases of survived strangulation were included in the study. One hundred and ten (82%) cases were cases of manual strangulation. Twenty-one (16%) victims were attacked by ligature strangulation while in three (2%) cases manual and ligature strangulation were combined. Fig. 1 shows the age and gender distribution of the victims. In 4 (3%) cases the victim was a child, the remaining 130 (97%) victims being adults. Most victims (32%) were between 20 and 30 years of age. Twenty (15%) of the victims were males, 114 (85%) were females. In 112 cases (83%) the victim was female and the suspect was male. All male victims were assaulted by men and in two cases victim and suspect were females. In 47 (35%) cases the strangulation was inflicted during a rape or a rape attempt. In seven cases no symptoms were described by the victim and no findings could be observed at the forensic examination. During the assault 27 (20%) of all victims reported having had dyspnea. Thirteen (10%) described that they ‘‘nearly’’ fainted whereas 15 (11%) reported having lost consciousness completely. Four (3%) of the victims claimed that they had lost urine during the assault. Fig. 2 gives an overview on all findings that were detectable at the time of examination. In 29 (21%) of all cases petechial hemorrhages were documented. Only in three of these cases petechiae were not seen in the conjunctivae but in other sites (buccal mucosa, areas of skin around the eyes). Table 1 shows a classification of all cases by findings and symptoms. The majority of cases showed superficial skin lesion and injury of soft tissue, pharynx and larynx. Ninetyfive cases (71%) showed a continuum of findings from superficial skin lesions to petechiae and signs of cerebral impairment. All cases in the study with extensive petechiae showed all other symptoms and findings supporting the assumption, that a fierce strangulation took place. In nine
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Fig. 1. Age and gender of victims.
cases, where the victims suffered a loss of consciousness and/or loss of urine, injuries of the neck as well as petechiae were documented. In six cases loss of consciousness was not associated with petechiae. Four of these victims however suffered a non-negligible trauma of the head which could explain that unconsciousness was not due to strangulation but to a cerebral concussion. Based on the forensic reports no clinical symptoms of neurological impairment or serious traumatism of the organs of the neck after the incident were observed. In none of the cases a clinical examination of the victim was, however, carried out.
4. Discussion No one would deny that strangulation is a dangerous form of assault. It would however be wrong to consider any grasp at the neck as life threatening. The threat for the victims life is greater with increasing intensity and duration of the assault. But when exactly does a pressure on the neck become a danger to the life of the victim? How much time and force is necessary? How can the intensity of the assault be proven by findings on the living victim after the incident? These are the essential questions in survived strangulation cases, to which the forensic expert has to answer in the court
Fig. 2. Findings on victims.
T. Plattner et al. / Forensic Science International 153 (2005) 202–207 Table 1 Frequency of groups of findings and symptoms and their combination Number of cases
Findings I
II
III
IV
7 33 44 9 9
No findings and symptoms X X X X X X X X X
X
17 6 4 3 1 1
X X X
X
X X X
X X X X
The cases on gray background representing a continuum of findings related to the intensity of the assault. I: superficial skin lesions (hyperemia, abrasions and intracutaneous bleeding); II: signs of soft tissue lesions or lesions of pharynx and larynx (hematomas, swelling, painful palpation, hoarseness, sore throat, radiologic demonstration of lesion such as fractures of hyoid bone and thyroid cartilage); III: petechial bleedings on conjunctivae, mucosal surfaces and facial skin; IV: signs of cerebral hypoxia (loss of consciousness, loss of urine, etc.).
room. The Swiss penal code for instance discerns between ‘‘simple-’’ and ‘‘severe bodily harm’’ in cases where a victim was injured and ‘‘endangerment of life’’ for potential lifethreatening situations without injury. In both ‘‘severe bodily harm’’ as well as ‘‘endangerment of life’’ – which are sanctioned by a considerably higher penalty than ‘‘simple bodily harm’’ – the main criterion is, that the victim was in an immediate life-threatening situation. ‘‘Endangerment of life’’ was the verdict by the Swiss Federal Court in a case of strangulation [31]. In this case the life-threatening character of the assault was based on victims statements on the duration of the attack and the presence of local abrasions and erythema on the skin. The forensic expert concluded in his statement, that the long duration of neck compression in this case would be associated with a high probability of a reflex cardiac death. The juridical qualification of the assault, the verdict and the degree of penalty can thus critically depend on the statement of the forensic expert as this case demonstrates. There are however no generally accepted evaluation criteria; this gives rise to an inconsistent assessment by forensic experts based on personal experience and opinion. An overview of all cases of survived strangulation at the Institute of Forensic Medicine of Bern, Switzerland between 1987 and 2002 has shown, that some experts would consider any grasp on the neck as potentially life threatening while others demand the presence of petechiae and/or unconsciousness as proof that the victim was in immediate danger to life. It has been shown in previous studies, that any judgement of intensity and duration of the strangulation by the injuries
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on the victim may be difficult and that different modes of strangulation are characterized by typical injuries [1,24,25]. This is supported by the results of our study. With reference to incidence and extent of findings and symptoms the results of our study are comparable to those by Strauch et al. [24]. A classification of all cases by the findings, as offered in Table 1, showed that a continuum of findings from superficial lesions to soft tissue traumatism and lesions of pharyngeal and laryngeal structures and signs of venous congestion and impaired cerebral functions were observed in the majority of cases (95 cases representing 71% of all cases). In most of these cases, manual strangulation on an uncovered neck (i.e. not protected by garment) took place. We concluded that the presence of superficial findings alone would speak for a relatively mild traumatisation and that with an increase of fierceness they would be combined with signs of soft tissue injury and injuries of pharynx and larynx as well as congestive petechiae and loss of consciousness in severe strangulation. In the remaining 37% of all cases, where an incontinuous pattern of findings was documented, the intensity of strangulation was difficult to judge. A thorough analysis of these cases showed, that the circumstances of the case, the mode of strangulation, the unspecificity of findings, the lapse of time between incident and examination, which can lead to disappearance of certain superficial findings and petechial hemorrhages [26], should be considered in each strangulation case. Ligature strangulation, especially when a broad and soft strangling object like a bath towel had been used, may show a lack of superficial lesions but can affect soft tissue (two cases in this study). The same can be stated for cases where the victim was strangled from behind by the suspects forearm (neck hold, ‘‘carotid sleeper’’ [32,33]) which was encountered in four cases. Petechiae should be combined with other strangulation findings and symptoms (class I, II, and IV findings) in order to be used as indicator for an intense assault. In cases with minor petechiae and no other signs of violent neck compression it should be considered, that they are not specific and may have other causes not related to strangulation [2,19,28,34–36]. On the other hand, the lack of positive signs of congestion at the time of examination may not exclude a severe strangulation in every case. Petechiae may vanish after 1–3 days after the incident [24,37]. It has been shown that a neck hold can result in a complete occlusion of carotid and vertebral arteriae [32,33,38]. In cases where a strangulation with the forearm (neck hold, ‘‘Carotid sleeper’’) took place, the rare possibility of occlusion of both venous and arterial blood vessels should therefore be considered [33]. Symptoms indicating an impaired cerebral function should be interpreted with caution because of their subjective nature. Loss of consciousness and/or incontinence should not be regarded as proof for a severe strangulation, if no other findings, namely petechiae, are present [24]. Other causes for loss of consciousness must be excluded
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[1,24]. If no symptoms of impaired cerebral function are reported but clear signs of congestion and other typical strangulation findings are observable, a severe and lifethreatening strangulation should not be excluded since, as previously discussed, congestive petechiae prove the high intensity and relatively long duration of the assault. Based on the results of this study and a review of the literature the authors propose the categorisation of survived strangulation in three degrees of severity based on objective findings on condition that a complete forensic medical examination was performed upon the surviving victim shortly (1–2 days) after the incident and the mode of strangulation is known: 1. Light strangulation Presence of class I findings at typical sites on the skin consistent with mode of strangulation (class I findings may lack in strangulation with the forearm and/or ligature strangulation with a broad and soft object). Moderate strangulation 2. Presence of class I findings at typical sites on the skin consistent with mode of strangulation (class I findings may lack in strangulation with the forearm and/or ligature strangulation with a broad and soft object) and class II findings. 3. Severe, life-threatening strangulation Presence of class I findings at typical sites on the skin consistent with mode of strangulation (class I findings may lack in strangulation with the forearm and/or ligature strangulation with a broad and soft object), class II findings and distinct class III findings with or without class IV findings. Class I findings. Superficial skin lesions (hyperemia, abrasions and intracutaneous bleeding). Class II findings. Signs of soft tissue lesions or lesions of pharynx and larynx (hematomas, swelling, painful palpation, hoarseness, sore throat, radiologic demonstration of lesion such as fractures of hyoid bone and thyroid cartilage). Class III findings. Petechial bleedings on conjunctivae, mucosal surfaces and facial skin. Class IV findings. Signs of cerebral hypoxia (loss of consciousness, loss of urine, etc.). The authors are aware that any categorisation of a very complex matter like strangulation is a simplification that may not live up to reality in particular cases. Each strangulation case should therefore be treated and assessed individually. This classification should be considered as a proposition in order to standardize the forensic assessment of survived strangulation. The value of this classification has yet to be proven in daily forensic routine and scrutinized by further prospective studies.
In addition to the forensic examination, a clinical examination and radiological imaging of the victim should be considered and recommended in any case of serious intensity of strangulation and evidence of relevant traumatism of the neck or other relevant injuries.
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