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Two cases of suicide by asphyxiation due to helium and argon
Forensic Science International 223 (2012) e27–e30
Contents lists available at SciVerse ScienceDirect
Forensic Science International journal homepage: www.elsevier.com/locate/forsciint
Case report
Two cases of suicide by asphyxiation due to helium and argon Frank Musshoff *, Lars Hagemeier, Katrin Kirschbaum, Burkhard Madea Institute of Forensic Medicine, Rheinische Friedrich-Wilhems-University, Bonn, Germany
A R T I C L E I N F O
A B S T R A C T
Article history: Received 17 July 2012 Received in revised form 25 August 2012 Accepted 28 August 2012 Available online 20 September 2012
Numerous death cases due to suffocation in a toxic or oxygen deficient gas atmosphere have been described in the literature, but unfortunately especially cases involving inert gases like helium are often presented without detailed toxicological findings. Observations on two suicides are reported, one by helium and the other by argon inhalation. During autopsies gas samples from the lungs were collected directly into headspace vials by a procedure ensuring minimal loss and dilution. Qualitative gas analyses were performed using headspace gas chromatography–mass spectrometry (HS-GC/MS). For carrier gas the commonly used helium was replaced by hydrogen. Qualitative positive results were obtained in the argon case, but the case involving helium revealed negative findings. The use of HS-GC/MS enables in principle to detect inert gases like argon or helium. However, a number of factors may later influence the results as, e.g. a longer period of time between death and sampling or pre-analytical artefacts during sampling of such highly volatile substances. In absence of analytical data supporting helium exposure, the causes of death in the actual cases were found to be asphyxia and in both cases the manner was suicide. ß 2012 Elsevier Ireland Ltd. All rights reserved.
Keywords: Helium Argon Suicide Headspace GC/MS Suffocation Asphyxia
1. Introduction Cases of suicide by asphyxiation with a plastic bag placed over the head – other kinds of confined space are motorcycle helmets or prepared filter masks – have been reported in the forensic literature over several decades [1,2]. An auxiliary method is the channelling of gases into a plastic bag leading to reduction or replacement of oxygen in the inhaled air and therefore accelerating death by suffocation. In 2002, Ogden and Wooten [3] described the first case of suicide by helium asphyxiation. Since that time apart from an accidental case [4] numerous suicides by helium asphyxiation have been reported worldwide. Unfortunately, in such case reports detailed toxicological findings are missing and the causes of death could be determined only by the circumstances of the cases [3,5–10]. Recently, Bittorf et al. [11] reported 4 cases of helium-associated suicides, and in 2 of them a determination of helium was successfully done. Previously in a review Howard et al. [12] summarised in detail several cases from the literature together with cases from North Carolina. Toxicological findings following an asphyxial suicide with helium in a plastic bag were described by Auwaerter et al. [13], who have also previously reported about analytical investigations in a death case by suffocation in an argon atmosphere [14].
* Corresponding author at: Institute of Forensic Medicine, University of Bonn, Stiftsplatz 12, 53111 Bonn, Germany. Tel.: +49 0228 738310; fax: +49 0228 738339. E-mail address: [email protected] (F. Musshoff). 0379-0738/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.forsciint.2012.08.049
Recently, Schaff et al. [15] demonstrated a procedure combining gas chromatography with thermal conductive detection for the analysis of helium in post mortem blood and tissue specimens. Suicides by use of argon have not been described until now, but argon is well known for euthanasia in animals [16,17]. There exists a report of accidental argon fatalities in a hospital [18] and also recently a fatality due to argon gas embolism during prostate cryosurgery has been described [19]. We report about toxicological findings in two suicides, one committed by helium and the other by argon inhalation.
2. Case history 2.1. Case 1 On her 30th birthday a female was found by her mother lying on her bed. A plastic bag was placed over her head corded around the neck. A flexible tube inside the bag was connected to a helium bottle, belonging to a commercially available helium balloon kit found in the bedroom. The hands of the deceased were bonded behind her back with a rope construction. A suicide note was found together with a testament. Autopsy results: Body of an adipose female, body mass 92.8 kg, body length 167.5 cm. No signs of external violence. Beginning putrefaction with green discolouration, slippage of skin, and marbling. Advanced putrefaction also of the internal organs. Liver steatosis. Splenomegalia.
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F. Musshoff et al. / Forensic Science International 223 (2012) e27–e30
Results obtained by chemical–toxicological routine analyses using immunological as well as gas chromatographic–mass spectrometric and high performance liquid chromatographic– mass spectrometric screening procedures: blood alcohol concentration 0.35 g/l, diazepam 0.10 mg/l, nordiazepam 0.04 mg/l (both in femoral blood).
helium gave no signal. This was also observed by Varlet and Augsburger [20], who recommended hydrogen as carrier gas. According to their results, the analysis of gas lighter than the carrier chromatographic gas can lead to saturation of the mass spectrometer (pumps are not efficient enough to pump these gases out from the MS) causing a decrease of sensitivity sufficient to cancel the acquisition.
2.2. Case 2 4. Results and discussion A 43-old man was found lying in the basement of his home. A plastic bag was placed over his head corded around the neck. A flexible tube inside the bag was connected to an argon bottle. Additionally a bottle of chloroform was found in this room as well as instructions to perform suicide written by an Australian physician. Autopsy results: Body of a male with 79 kg body mass, 166.5 cm body length. No signs of external violence. Petechial haemorrhages in the conjunctivae, Tardieu spots, congestion of internal organs. Splenomegalia. Brain oedema. No relevant pre-existing diseases. Apart from a citalopram concentration of 0.018 mg/l, chemical– toxicological routine analyses revealed negative results including for chloroform. 3. Materials and methods 3.1. Collection of gas samples from the lungs The procedure described by Auwaerter et al. [13] was found not useful during autopsy because piercing of long and thick metal needles into the side of the pail to manipulate the lungs and to press out gas resulted in non gas-tight holes in the pail. Therefore, the procedure was modified as follows: Each lung was collected in a separate plastic pail filled with water except for a very small volume. The pail was conversely plunged into a basin of water. The residual air was sucked out of the pail and discarded using a syringe fitted with a T-piece. Then the lung was manipulated with scissors and compressed by hand so that air/gases escaping from the lungs were collected in the top of the inverted pail. The gas volumes escaping from the lungs were collected with the syringe and directly pressed into a 20-ml-headspace vial which had completely been filled with water and crimped closely under water before. For this purpose the septum of the vial cap was punctured with a second cannula, while holding the vial with the bottom up and filling the gas sample in via the septum, so that the water was displaced through the second cannula. The procedure is demonstrated in parts in Fig. 1. For comparison, the same procedure was also carried out with another autopsy case and additionally helium/argon gas was directly sampled into headspace vials. 3.2. Gas chromatography–mass spectrometry Gas analyses were performed on a Agilent model 6890 series Plus GC, in combination with an Agilent 5973 N MSD MS (Chromtech, Idstein, Germany) using a fused-silica capillary column (Optima-1-MS (Macherey-Nagel, Dueren, Germany), 30 m 0.25 mm i.d., 0.25-mm film thickness; injector temperature 100 8C; oven temperature 120 8C isothermal; interface temperature 200 8C). Injection was carried out in a splitless injection mode (split ratio 3:1), and nitrogen was used for carrier gas instead of the commonly used helium at a flow rate of 1.0 ml/ min. The following ions were detected in selected ion monitoring (SIM): m/z = 4 (helium), 16 (methane), 18 (water), 32 (oxygen), 40 (argon), 44 (carbon dioxide). Using nitrogen as carrier gas, a negative peak appeared at the expected helium retention time and the extracted ion m/z = 4 from
In Fig. 2, the obtained GC/MS chromatograms of gas samples from the deceased, from a comparison case without pre-mortal helium exposure, and from helium directly filled into a headspace vial are shown. The standard revealed a positive result, but in the case under investigation as well as in the case without pre-mortal helium inhalation negative results were achieved. As demonstrated in Fig. 3, positive results were obtained in the argon case, with a significant peak for argon in comparison to the negative autopsy case. The use of HS-GC/MS enables in principle to detect inert gases like argon or helium. The approach is of qualitative nature and there is not a secondary confirmation method employed. But in combination with the paraphernalia found at the scene, this should affect enough information for cause of death ruling. Rather important is an appropriate sampling technique at autopsy and a convenient analytical procedure (e.g. GC/MS analysis using nitrogen as carrier gas). However, a number of factors may influence the results, as e.g. a longer period of time between death and sampling or pre-analytical artefacts when sampling such highly volatile substances. Even in the presented case involving helium despite of a potentially appropriate sampling technique only negative results were obtained. We cannot exclude a loss of helium by sampling in case 1 because we did not have an internal standard for a definite proof. Otherwise, the post mortem interval until sampling was about 6–7 days in this case and putrefaction was observed which could probably influence further analyses. However, the death scene clearly gave indications and in both cases the cause of death was determined to be due to asphyxiation (in case 1 in absence of analytical data without a proof for helium inhalation), caused by environmental hypoxia. The manner of death was designated suicide. In general, classic but non specific signs of asphyxia include petechial haemorrhages as seen here in case 2, congestion and oedema of the lungs, cyanosis, dilatation of the right ventricle of the heart, and fluidity of blood [21]. Plastic bag suffocation generally does not leave externally visible marks. The only possible indicators are certain spaces in the livores or merely an impression or a ligature mark on the skin caused by tight fixation of the plastic bag around the neck [22]. However, petechial haemorrhages in the conjunctivae or the mucosa of the mouth are normally rare findings. We agree with Jones et al. [23], who emphasised that in cases of plastic bag suffocation an autopsy is not complete until toxicological analyses are performed. As positive morphologic evidence is usually absent, investigations at the death scene and the deceased’s environment become extremely important. The cause of death can only be determined by morphological evidence at the death scene and further detailed toxicological analyses. In publications of suicide guides [24,25] or sites on the Internet [26] insufflation of an inert gas into a suffocating plastic bag are recommended as means to hasten death. It was also reported that the numbers of such suicides increased clearly during the last recent years [12,27]. Both cases presented here occurred within 2 months. In general, precaution has to be taken because in so-called suicide fora on the Internet it is even encouraged that relatives
F. Musshoff et al. / Forensic Science International 223 (2012) e27–e30
Fig. 1. Illustration of the sampling procedure.
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F. Musshoff et al. / Forensic Science International 223 (2012) e27–e30
unclarified because such a sophisticated sampling (e.g. in air-tight vials) needed would never be done. References
Fig. 2. The helium case: headspace GC–MS-SIM chromatograms from the deceased (lungs), from a comparison case without pre-mortal helium exposure, and from helium directly filled into a headspace vial.
Fig. 3. The argon case: headspace GC–MS-SIM chromatograms from the deceased (lungs), from a comparison case without pre-mortal argon exposure, and from argon directly filled into a headspace vial.
should remove used equipment like helium cylinders, plastic bags and flexible tubes. By this, suicide could be concealed for insurance-legal aspects and additionally the discovery of the deceased would include more dignity. From the forensic point of view it has to be acknowledged that such cases would well remain
[1] G. Skold, Fatal suffocation in plastic bag, Dtsch. Z. Gesamte Gerichtl. Med. 59 (1967) 42–46. [2] C.J. Polson, D.J. Gee, Plastic bag suffocation, Z. Rechtsmed. 70 (1972) 184–190. [3] R.D. Ogden, R.H. Wooten, Asphyxial suicide with helium and a plastic bag, Am. J. Forensic Med. Pathol. 23 (2002) 234–237. [4] K. Yoshitome, T. Ishikawa, S. Inagaki, Y. Yamamoto, S. Miyaishi, H. Ishizu, A case of suffocation by an advertising balloon filled with pure helium gas, Acta Med. Okayama 56 (2002) 53–55. [5] T. Gilson, B.O. Parks, C.M. Porterfield, Suicide with inert gases: addendum to Final Exit, Am. J. Forensic Med. Pathol. 24 (2003) 306–308. [6] K.E. Gallagher, D.M. Smith, P.F. Mellen, Suicidal asphyxiation by using pure helium gas: case report, review, and discussion of the influence of the Internet, Am. J. Forensic Med. Pathol. 24 (2003) 361–363. [7] C.A. Scho¨n, T. Ketterer, Asphyxial suicide by inhalation of helium inside a plastic bag, Am. J. Forensic Med. Pathol. 28 (2007) 364–367. [8] M. Grassberger, A. Krauskopf, Suicidal asphyxiation with helium: report of three cases, Wien. Klin. Wochenschr. 119 (2007) 323–325. [9] R.D. Ogden, Observation of two suicides by helium inhalation in a prefilled environment, Am. J. Forensic Med. Pathol. 31 (2010) 156–161. [10] R.D. Ogden, W.K. Hamilton, C. Whitcher, Assisted suicide by oxygen deprivation with helium at a Swiss right-to-die organisation, J. Med. Ethics 36 (2010) 174–179. [11] A. Bittorf, D. Thieme, K. Pu¨schel, P. Friedrich, O. Peschel, D. Rentsch, A. Bu¨ttner, Tod in Tu¨ten – Heliumassoziierter Suizid in der rechtsmedizinischen Praxis, Z. Rechtsmed. 22 (1) (2012) 5–11. [12] M.O. Howard, M.T. Hall, J.D. Edwards, M.G. Vaughn, B.E. Perron, R.E. Winecker, Suicide by asphyxiation due to helium inhalation, Am. J. Forensic Med. Pathol. 32 (2011) 61–70. [13] V. Auwaerter, M.G. Perdekamp, J. Kempf, U. Schmidt, W. Weinmann, S. Pollak, Toxicological analysis after asphyxial suicide with helium and a plastic bag, Forensic Sci. Int. 170 (2007) 139–141. [14] V. Auwarter, F. Pragst, H. Strauch, Analytical investigations in a death case by suffocation in an argon atmosphere, Forensic Sci. Int. 143 (2004) 169–175. [15] J.E. Schaff, P.R. Karas, L. Marinetti, A gas chromatography–thermal conductivity detection method for helium detection in postmortem blood and tissue specimens, J. Anal. Toxicol. 36 (2012) 112–115. [16] G.H. Poole, D.L. Fletcher, A comparison of argon, carbon dioxide, and nitrogen in a broiler killing system, Poult. Sci. 74 (1995) 1218–1223. [17] J. Sharp, T. Azar, D. Lawson, Comparison of carbon dioxide, argon, and nitrogen for inducing unconsciousness or euthanasia of rats, J. Am. Assoc. Lab. Anim. Sci. 45 (2006) 21–25. [18] F.P. Smith, Multiple deaths from argon contamination of hospital oxygen supply, J. Forensic Sci. 32 (1987) 1098–1102. [19] M. Sandomirsky, J.A. Crifasi, C. Long, E.K. Mitchell, Case report of fatal complication in prostatic cryotherapy: first reported death due to argon gas emboli, Am. J. Forensic Med. Pathol. (2010). [20] V. Varlet, M. Augsburger, 2011, personal communication. [21] B. Knight, Forensic Pathology, Oxford University Press, New York, 1996. [22] W. Grellner, S. Anders, M. Tsokos, J. Wilske, Suicide with exit bags: circumstances and special problem situations in assisted suicide, Arch. Kriminol. 209 (2002) 65–75. [23] L.S. Jones, J.P. Wyatt, A. Busuttil, Plastic bag asphyxia in southeast Scotland, Am. J. Forensic Med. Pathol. 21 (2000) 401–405. [24] D. Humphry, Final Exit – The Practicalities of Self-Deliverance and Assisted Suicide for the Dying, Delta, New York, 2002. [25] T. James, How to Commit a Successful Suicide, Lulu Enterprises Inc., Raleigh, NC, 2010. [26] Patients Rights Council, http://www.patientsrightscouncil.org/site/hemlockand-caring-friends/ (accessed 23.12.11). [27] A. Austin, C. Winskog, C. van den Heuvel, R.W. Byard, Recent trends in suicides utilizing helium, J. Forensic Sci. 56 (2011) 649–651.
Contents lists available at SciVerse ScienceDirect
Forensic Science International journal homepage: www.elsevier.com/locate/forsciint
Case report
Two cases of suicide by asphyxiation due to helium and argon Frank Musshoff *, Lars Hagemeier, Katrin Kirschbaum, Burkhard Madea Institute of Forensic Medicine, Rheinische Friedrich-Wilhems-University, Bonn, Germany
A R T I C L E I N F O
A B S T R A C T
Article history: Received 17 July 2012 Received in revised form 25 August 2012 Accepted 28 August 2012 Available online 20 September 2012
Numerous death cases due to suffocation in a toxic or oxygen deficient gas atmosphere have been described in the literature, but unfortunately especially cases involving inert gases like helium are often presented without detailed toxicological findings. Observations on two suicides are reported, one by helium and the other by argon inhalation. During autopsies gas samples from the lungs were collected directly into headspace vials by a procedure ensuring minimal loss and dilution. Qualitative gas analyses were performed using headspace gas chromatography–mass spectrometry (HS-GC/MS). For carrier gas the commonly used helium was replaced by hydrogen. Qualitative positive results were obtained in the argon case, but the case involving helium revealed negative findings. The use of HS-GC/MS enables in principle to detect inert gases like argon or helium. However, a number of factors may later influence the results as, e.g. a longer period of time between death and sampling or pre-analytical artefacts during sampling of such highly volatile substances. In absence of analytical data supporting helium exposure, the causes of death in the actual cases were found to be asphyxia and in both cases the manner was suicide. ß 2012 Elsevier Ireland Ltd. All rights reserved.
Keywords: Helium Argon Suicide Headspace GC/MS Suffocation Asphyxia
1. Introduction Cases of suicide by asphyxiation with a plastic bag placed over the head – other kinds of confined space are motorcycle helmets or prepared filter masks – have been reported in the forensic literature over several decades [1,2]. An auxiliary method is the channelling of gases into a plastic bag leading to reduction or replacement of oxygen in the inhaled air and therefore accelerating death by suffocation. In 2002, Ogden and Wooten [3] described the first case of suicide by helium asphyxiation. Since that time apart from an accidental case [4] numerous suicides by helium asphyxiation have been reported worldwide. Unfortunately, in such case reports detailed toxicological findings are missing and the causes of death could be determined only by the circumstances of the cases [3,5–10]. Recently, Bittorf et al. [11] reported 4 cases of helium-associated suicides, and in 2 of them a determination of helium was successfully done. Previously in a review Howard et al. [12] summarised in detail several cases from the literature together with cases from North Carolina. Toxicological findings following an asphyxial suicide with helium in a plastic bag were described by Auwaerter et al. [13], who have also previously reported about analytical investigations in a death case by suffocation in an argon atmosphere [14].
* Corresponding author at: Institute of Forensic Medicine, University of Bonn, Stiftsplatz 12, 53111 Bonn, Germany. Tel.: +49 0228 738310; fax: +49 0228 738339. E-mail address: [email protected] (F. Musshoff). 0379-0738/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.forsciint.2012.08.049
Recently, Schaff et al. [15] demonstrated a procedure combining gas chromatography with thermal conductive detection for the analysis of helium in post mortem blood and tissue specimens. Suicides by use of argon have not been described until now, but argon is well known for euthanasia in animals [16,17]. There exists a report of accidental argon fatalities in a hospital [18] and also recently a fatality due to argon gas embolism during prostate cryosurgery has been described [19]. We report about toxicological findings in two suicides, one committed by helium and the other by argon inhalation.
2. Case history 2.1. Case 1 On her 30th birthday a female was found by her mother lying on her bed. A plastic bag was placed over her head corded around the neck. A flexible tube inside the bag was connected to a helium bottle, belonging to a commercially available helium balloon kit found in the bedroom. The hands of the deceased were bonded behind her back with a rope construction. A suicide note was found together with a testament. Autopsy results: Body of an adipose female, body mass 92.8 kg, body length 167.5 cm. No signs of external violence. Beginning putrefaction with green discolouration, slippage of skin, and marbling. Advanced putrefaction also of the internal organs. Liver steatosis. Splenomegalia.
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F. Musshoff et al. / Forensic Science International 223 (2012) e27–e30
Results obtained by chemical–toxicological routine analyses using immunological as well as gas chromatographic–mass spectrometric and high performance liquid chromatographic– mass spectrometric screening procedures: blood alcohol concentration 0.35 g/l, diazepam 0.10 mg/l, nordiazepam 0.04 mg/l (both in femoral blood).
helium gave no signal. This was also observed by Varlet and Augsburger [20], who recommended hydrogen as carrier gas. According to their results, the analysis of gas lighter than the carrier chromatographic gas can lead to saturation of the mass spectrometer (pumps are not efficient enough to pump these gases out from the MS) causing a decrease of sensitivity sufficient to cancel the acquisition.
2.2. Case 2 4. Results and discussion A 43-old man was found lying in the basement of his home. A plastic bag was placed over his head corded around the neck. A flexible tube inside the bag was connected to an argon bottle. Additionally a bottle of chloroform was found in this room as well as instructions to perform suicide written by an Australian physician. Autopsy results: Body of a male with 79 kg body mass, 166.5 cm body length. No signs of external violence. Petechial haemorrhages in the conjunctivae, Tardieu spots, congestion of internal organs. Splenomegalia. Brain oedema. No relevant pre-existing diseases. Apart from a citalopram concentration of 0.018 mg/l, chemical– toxicological routine analyses revealed negative results including for chloroform. 3. Materials and methods 3.1. Collection of gas samples from the lungs The procedure described by Auwaerter et al. [13] was found not useful during autopsy because piercing of long and thick metal needles into the side of the pail to manipulate the lungs and to press out gas resulted in non gas-tight holes in the pail. Therefore, the procedure was modified as follows: Each lung was collected in a separate plastic pail filled with water except for a very small volume. The pail was conversely plunged into a basin of water. The residual air was sucked out of the pail and discarded using a syringe fitted with a T-piece. Then the lung was manipulated with scissors and compressed by hand so that air/gases escaping from the lungs were collected in the top of the inverted pail. The gas volumes escaping from the lungs were collected with the syringe and directly pressed into a 20-ml-headspace vial which had completely been filled with water and crimped closely under water before. For this purpose the septum of the vial cap was punctured with a second cannula, while holding the vial with the bottom up and filling the gas sample in via the septum, so that the water was displaced through the second cannula. The procedure is demonstrated in parts in Fig. 1. For comparison, the same procedure was also carried out with another autopsy case and additionally helium/argon gas was directly sampled into headspace vials. 3.2. Gas chromatography–mass spectrometry Gas analyses were performed on a Agilent model 6890 series Plus GC, in combination with an Agilent 5973 N MSD MS (Chromtech, Idstein, Germany) using a fused-silica capillary column (Optima-1-MS (Macherey-Nagel, Dueren, Germany), 30 m 0.25 mm i.d., 0.25-mm film thickness; injector temperature 100 8C; oven temperature 120 8C isothermal; interface temperature 200 8C). Injection was carried out in a splitless injection mode (split ratio 3:1), and nitrogen was used for carrier gas instead of the commonly used helium at a flow rate of 1.0 ml/ min. The following ions were detected in selected ion monitoring (SIM): m/z = 4 (helium), 16 (methane), 18 (water), 32 (oxygen), 40 (argon), 44 (carbon dioxide). Using nitrogen as carrier gas, a negative peak appeared at the expected helium retention time and the extracted ion m/z = 4 from
In Fig. 2, the obtained GC/MS chromatograms of gas samples from the deceased, from a comparison case without pre-mortal helium exposure, and from helium directly filled into a headspace vial are shown. The standard revealed a positive result, but in the case under investigation as well as in the case without pre-mortal helium inhalation negative results were achieved. As demonstrated in Fig. 3, positive results were obtained in the argon case, with a significant peak for argon in comparison to the negative autopsy case. The use of HS-GC/MS enables in principle to detect inert gases like argon or helium. The approach is of qualitative nature and there is not a secondary confirmation method employed. But in combination with the paraphernalia found at the scene, this should affect enough information for cause of death ruling. Rather important is an appropriate sampling technique at autopsy and a convenient analytical procedure (e.g. GC/MS analysis using nitrogen as carrier gas). However, a number of factors may influence the results, as e.g. a longer period of time between death and sampling or pre-analytical artefacts when sampling such highly volatile substances. Even in the presented case involving helium despite of a potentially appropriate sampling technique only negative results were obtained. We cannot exclude a loss of helium by sampling in case 1 because we did not have an internal standard for a definite proof. Otherwise, the post mortem interval until sampling was about 6–7 days in this case and putrefaction was observed which could probably influence further analyses. However, the death scene clearly gave indications and in both cases the cause of death was determined to be due to asphyxiation (in case 1 in absence of analytical data without a proof for helium inhalation), caused by environmental hypoxia. The manner of death was designated suicide. In general, classic but non specific signs of asphyxia include petechial haemorrhages as seen here in case 2, congestion and oedema of the lungs, cyanosis, dilatation of the right ventricle of the heart, and fluidity of blood [21]. Plastic bag suffocation generally does not leave externally visible marks. The only possible indicators are certain spaces in the livores or merely an impression or a ligature mark on the skin caused by tight fixation of the plastic bag around the neck [22]. However, petechial haemorrhages in the conjunctivae or the mucosa of the mouth are normally rare findings. We agree with Jones et al. [23], who emphasised that in cases of plastic bag suffocation an autopsy is not complete until toxicological analyses are performed. As positive morphologic evidence is usually absent, investigations at the death scene and the deceased’s environment become extremely important. The cause of death can only be determined by morphological evidence at the death scene and further detailed toxicological analyses. In publications of suicide guides [24,25] or sites on the Internet [26] insufflation of an inert gas into a suffocating plastic bag are recommended as means to hasten death. It was also reported that the numbers of such suicides increased clearly during the last recent years [12,27]. Both cases presented here occurred within 2 months. In general, precaution has to be taken because in so-called suicide fora on the Internet it is even encouraged that relatives
F. Musshoff et al. / Forensic Science International 223 (2012) e27–e30
Fig. 1. Illustration of the sampling procedure.
e29
e30
F. Musshoff et al. / Forensic Science International 223 (2012) e27–e30
unclarified because such a sophisticated sampling (e.g. in air-tight vials) needed would never be done. References
Fig. 2. The helium case: headspace GC–MS-SIM chromatograms from the deceased (lungs), from a comparison case without pre-mortal helium exposure, and from helium directly filled into a headspace vial.
Fig. 3. The argon case: headspace GC–MS-SIM chromatograms from the deceased (lungs), from a comparison case without pre-mortal argon exposure, and from argon directly filled into a headspace vial.
should remove used equipment like helium cylinders, plastic bags and flexible tubes. By this, suicide could be concealed for insurance-legal aspects and additionally the discovery of the deceased would include more dignity. From the forensic point of view it has to be acknowledged that such cases would well remain
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