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The epidemiology of homicide-suicide (dyadic death)
ELSEVIER
Forensic Science International 71 (1995) 117-122
Forensic Science international
The epidemiology of homicide-suicide (dyadic death) C.M. Milroy university of Sheffield, The Medico-Legal
Centre, Watery Street. Sheffield, S3 7ES, (IK
Received 20 June 1994; revision received 2 September 1994; accepted 15 September 1994
Abstract
The national and international rates of homicide and homicide-suicide (dyadic death) have beenstudied by examination of the available literature. The rates of homicide-suicide episodes betweendifferent countries showed considerable variation, though not as great as overall homicide rates. Despite the variation the features of the episodeswere similar, with a man usually killing his spouse and/or children with a firearm. The commonest motive for killing is jealousy and/or revenge, often as the result of a breakdown in the spousal relationship. Keywords: Homicide; Suicide; Dyadic death; Spousal killing; Jealousy; Revenge; Firearms; Carbon monoxide poisoning
1. Introduction There has been increasing interest over the last few years in the phenomenon of homicide-suicide, with a number of papers reporting on these episodes. In 1983, Coid examined the published data on homicide-suicide, and proposed ‘laws’ relating to homicide-suicide and mentally abnormal homicide [ 11.The laws were as follows:
1. the higher the rate of homicide in a population, the lower the percentage of offenders who are found (a) to be mentally abnormal and (b) to have committed suicide; 2. the rate of mentally abnormal offenders and those who commit suicide appears to be the same in different countries, despite considerable differences in the overall rates of homicide; and 0379-0738/95/%09.50 0 1995 Elsevier Science Ireland Ltd. All rights reserved SSDI 0379-0738(94)01648-O
118
C. hf. Milroy/Forensic
Sci. ht. 71 (1995) 117-122
3. there is someindication that the rate of mentally abnormal offenders, and those who commit suicide, remains the same,despite a fluctuation in the overall rate over time. This paper examines the published data on homicide-suicide, updating the information available to Coid, and examines whether Coid’s laws are still applicable with respect to homicide-suicide. 2. Methods Published papers reporting the phenomenon of homicide-suicide were examined. Papers on homicide which contained information on suicide of assailants were also examined. These data were also compared with my own studies undertaken on homicide-suicide in Yorkshire and Humberside, England. Data on homicide in England and Wales was obtained from official Government publications. Other government publications were used, where obtainable. 3. Results Table 1 shows the results of the published data on homicide and homicide-suicide [2-261. For comparison, rates of homicide-suicide episodes are shown in Fig. 1. 4. Discussion The results show that there is a wide variation in the rates of homicide. There is lessvariation in the rates of homicide-suicide. With countries with a high rate of homicide the percentageof homicide-suicide is low. Therefore, the first of Coid’s laws remains true. The secondlaw holds true to a certain extent, as there is lessof a variation in rates of homicide-suicide episodes than in overall homicide rates. However, when one closely examinesthe rates, it can be seenthat there is still considerable variation between some published data, Miami having a rate eight times higher than rates in England and Wales (and Yorkshire and Humberside) over a similar period. The data from the USA, and to a lesser extent other countries, suggest that with higher homicide rates there is a higher rate of homicide-suicide. Whether this is due to higher rates of violence in those societies,or due to the easewith which the killings can be achieved, is not clear. On the whole those countries with higher rates of homicide-suicide are those in which the percentage of killing with firearms is very high. Availability of weapons may therefore be a factor. In the UK, the replacement of toxic domestic coal gas with ‘natural’ gas, which does not contain carbon monoxide, appears to be a significant reason for the low numbers of female killers in the series from Yorkshire and Humberside [19,27] compared with the study of West [15], who found 40% of killers were female, with most using carbon monoxide poisoning as the method of killing. It is more difficult to study whether the rates of homicide-suicide vary from year to year in different countries. However, the data from England and Wales supports
119
C. M. Milroy /Forensic Sci. ht. 71 (1995) 117-122
Table 1 National and international rates of homicide-suicide Country
Years
Homicide rate per looooo
Homicidesuicide (%)
Homicidesuicide rate per looooo
USA Atlanta [2] USA Washington [3] USA Miama [4] USA Houston [5] USA Los Angeles [6] USA N. Carolina [7] USA Albuquerque [8] USA Philadelphia [9] USA Kentucky [lo] Bermuda [I] Finland [ 1l] Australia [ 151 Scotland [141a Australia [IS] Hong Kong [16] Canada [ 171 New Zealand [18] England, Yorkshire & Humberside [ 191 Canada [20] England & Wales [21] Israel (Oriental Jews) [22] Denmark, Copenhagen [23] England & Wales 1211 Denmark [24] Iceland [25] Sweden [26] Israel (Western Jews) [22]
1988-1991 1974-1975 1977-1985 1969 1970-1979 1972-1977 1978-1987 1948-1952 1985-1990 1920-1979 1955-1970 1989-1991 1986-1990 1959-1960 1961-1971 1968 1976-1989 1975-1992
38.8 29.3 27.1 23.3 17.1 16.1 12 6.1 5 2.35 2.2 2 1.75 1.7 1.57 1.5 1.5 1.5
1.4 1.5 2.21 1.8 2.1 l-2 4 3.6 6 5.5 8 8 3 22 5 18 3.4 4.6
0.46 0.43 0.55 0.42 0.36 0.19 0.25 0.21 0.3 0.13 0.18 0.16 0.05 0.36 0.07 0.27 0.05 0.07
1961-1966 1980-1990 1950-1964 1968-1983 1969-1979 1946-1970 1900-1979 1970-1981 1950-1964
1.36 1.11 1.07 0.99 0.88 0.79 0.72 0.7 0.59
15.6 7.2 25.6 8 8.2 30 8.5 15.6 67.8
0.21 0.07 0.27 0.08 0.07 0.2 0.06 0.09 0.4
aExcludes Lockerbie killings. There is somediscrepancy between the rates of homicide, percentage of homicide-suicide and the rate of homicide-suicide.This is becausemost authors calculate the homicide rate from the number of victims but the homicide-suicide rate from the number of episodes.There is also some rounding up of numbers.
Coid’s third law. Since Coid published his paper in 1983 the homicide rate has increased by 20%. Despite this increase, there has been no significant change in the rate of suicide among assailants. Indeed, there has been little change in the number of assailants who commit suicide over the last 30 years, despite the annual increase in homicide [19,27]. It would be interesting to see how data from other countries compares with the data from England and Wales. In 1992,Marzuk and colleaguesproposed a classification of homicide-suicide [28]. This is shown in Table 2. The classification is based on the type of relationship between the victim and perpetrator, and based on the perpetrator. The commonest type for homicide-suicide is spousal killing, with the man killing his wife, because
120
C. hf. Milroy/Forensic
Sri. ht. 71 (1995) 117-122
INTERNATIONAL HOMICIDE - SUICIDE RATES SCOTLAND 1957-195s NEWEEALAND saYrLAND1!MI6-9o KImAND YORKSHIRE AND HUMBERSIDE U.K. HONG KONG ENGLAND AND WALES 1%9-79 ENGLAND AND WALES l!MbMO DENMARK (COPENBAGBN) 1%&83 SWEDEN
ENGIANDANDwALEs 1991 ENGLANDANDWALIBENGLAND AND WALES MS&S!3 BERMUDA AUSIRALIA l!mal FINLAND NORTH CAROLINA U.S.A.
DENMARKI~~~~ CANADA 191148 PHILADELPHIA U.S.A. ALBUQUBRQUB U.S.A. I!sRAEL (ORIENTAL JEWS) CANADA 1%6 KENTUCKY U.S.A. AU~195%0 LOS ANGELES USA. ~=vJEws) HOUSI’ON U.S.A. WASIilNCI’0NU.S.A ATLANI’AUJ3.A.
as
.l
.15
3
.25
3
35
A
A5
.!!
55
06
PER 100,000 Fig. 1. International homicide-suicide rates.
of the breakdown of the relationship with resultant jealousy and revenge. Another common type is the killing of the children by their father or mother, with an element of misplaced altruism. The father is the most common perpetrator, though West’s study found women to be the assailants who most frequently killed their children. Alcohol intoxication of the perpetrator is a significant factor. Marzuk and colleaguesrecorded that the epidemiology of homicide-suicide in England was different from other countries, based on West’s results. However, the more recent studies from England do not indicate this, and have shown similar features to other studies, with male killers forming the vast majority, their spouse the most frequent victim
C. hf. Milroy/Forensic Sci. ht. 71 (1995) 117-122
121
Table 2 Classification of homicide-suicide (Matzuk et al. [28]) Type of relationship I. Spousal or consortia1 Perpetrator (a) Spouse (b) Consort Type of homicide (i) Uxoricidal (spouse-killing) (ii) Consortia1 (killing of lover) II Familial Perpetrator (a) Mother (b) Father (c) Child (< 16 years) (d) Other family member Type of homicide (i) Neonaticide (child ~24 h) (ii) Infanticide (child > I day, < I year) (iii) Pedicide (child > I year, < I6 years) (iv) Adult family member III Extrafamilial Class A Amorous jealousy B Mercy killing C Altruistic or extended suicide D Family, financial or social stressors E Retaliation F Other G Unspecified
[19,27]. A significant subgroup of male killers will kill their entire family, so called ‘family annihilators’. Hanslick and Koponen [2] have recently proposed modifications to the classification, though the basis of the classification is the same. Other patterns seen are the killing of an invalid or ill spouse in elderly couples, the victim usually being the woman, and killing becauseof financial stress. Mental illness is a significant factor in someepisodes,with depressivedisorders the most important. Killers of strangers are a rare phenomenon, but include mass killers who kill five or more victims in one episode. Serial killers, who kill three or more people on separate occasions, do not usually commit suicide. Overall homicide-suicide episodes show similar characteristics in the majority of published series. However, there is more variation in the rate of homicide-suicide episodesthan previously reported. This may partly be accounted for by availability of methods of killing. Cultural factors may play a part, but the question then arises
122
C. M. Milroy / Forensic Sci. Ini. 71 (1995) 117-122
as to how homicide-suicide episodes with similar characteristics in terms of the reasons for killing and the participants in the episodes should have different rates. Marzuk and colleagues called for more study of this phenomenon and suggesteda multi-disciplinary approach. These episodes are of interest to all professionals engagedin the investigation of crime and death, and present great opportunities for such a multi-disciplinary study. References [I] [2] [3] [4] [5] [6] [7] [8] [9] [IO]
[I I] [12] (131 [14] [15] [16] (171 [I81 [!9] [20] [21] [22] [23] [24] [25] [26] (271 [28]
J. Coid, The epidemiology of abnormal homicide and murder followed by suicide. Psycho/. Med., 13 (1983) 855-860. R. Hanslick and M. Koponen, Murder-suicide in Fulton County, Georgia: comparison with a recent report and proposed typology. Am. J. Forensic. Med. Pathol., 15 (I 994) !68- 173. A.L. Berman, Dyadic death: murder-suicide. Suicide Life Threat. Behav., 9 (1979) 15-23. A.R. Copeland, Dyadic death - revisited. J. Forensic. Sci., 25 (1985) 181-188. H.P. Lundsgaarde, Murder in Space City, Oxford University Press, New York, 1977. N.H. Allen, Homicide followed by suicide: Los Angeles, 1970-1979. Suicide L@ Threat. Behav., 13 (1983) 155-163. S. Palmer and J.A. Humphrey, Offender-victim relationships in criminal homicide followed by offender’s suicide, North Carolina, 1972-1977. Suicide Life Threat. Behav., 10 (1980) !06- 118. M. Rosenbaum, The role of depression in couples involved in murder-suicide and homicide. Am. J. Psychiar., 147 (1990) 1036-1039. M.E. Wolfgang, An analysis of homicide-suicide. J. C/in. Exp. Psychoparhol., 19 (1958) 208-218. S. Currens, T. Fritsch, D. Jones, G. Bush, J. Vance, K. Frederich, R. Adams, M. Adkins, J. Bothe, G. Murphy, C. Webb and R. Finger, Homicide followed by suicide - Kentucky, 1985-1990. M.M. WI?., 40 (1991) 652-659. M. Virkkunen, Suicide linked to homicide. Psychiatr. Q., 48 (1974) 276-282. H. Strang, Homicides in Australia 1989-1990, Australian Institute of Criminology, Canberra, 1991. H. Strang, Homicides in Australia 1990-1991, Australian Institute of Criminology, Canbarra, 1992. Scottish Office Homicide in Scotland 1986-1990. Sfarisrical Bull. Criminal Justice series, Scottish Office, Edinburgh, 1991. D.J. West, Murder Followed by Suicide, Heinemann, London, 1965. M. Wong and K. Singer, Abnormal homicide in Hong Kong. B. J. Psychiar., 123 (1973) 295-298. C. Greenland, Evaluation of violence and dangerous behaviour associated with mental illness. Semin. Psychiar., 3 (1971) 685-687. J. Christiansen, A. Still, T.D. Koelmeyer, Homicides offenders in Auckland, New Zealand. Am. J. Forensic. Med. Pathol., 14 (1993) 65-69. C.M. Milroy, Homicide followed by suicide (dyadic death) in Yorkshire and Humberside. Med. Sci. Law, 33 (1993) 167-171. B. Schloss and N.A. Giesbrecht, Murder in Canada. A report on capital and non-capital murder statistics, Centre of Criminology, University of Toronto, Toronto, 1972. Home Office, Criminal Statistics England and Wales 1992, HMSO, London, 1993. SF. Landau, Pathologies among homicide offenders. Br. J. Criminal., 15 (1975) 157-166. P. Gottlieb, P. Kramp and G. Garbrielsen, The practice of forensic psychiatry in cases of homicide in Copenhagen, 1959 to 1983. Acra Psychiatr. Stand., 76 (1987) 514-522. J.P. Hart Hansen, Drab i Danmark. 1946-1970, Munksgaard, Copenhagen, 1974. G.H. Gudjonsson and H. Petursson, Some criminological and psychiatric aspects of homicide in Iceland. Med. Sci. Law, 22 (1982) 91-98. P. Lundqvist, Criminal homicide in Northern Sweden 1970-81: alcohol intoxication, alcohol abuse and mental disease. Inc. J. Law Psychiar., 8 (1985) 19-37. C.M. Milroy, Reasons for homicide and suicide in episodes of dyadic death in Yorkshire and Humberside. Med. Sci. Law, (in press) P. Marzuk, K. Tardiff and C.S. Hirsch, The epidemiology of murder-suicide. JAMA, 267 (1992) 3179-3183.
Forensic Science International 71 (1995) 117-122
Forensic Science international
The epidemiology of homicide-suicide (dyadic death) C.M. Milroy university of Sheffield, The Medico-Legal
Centre, Watery Street. Sheffield, S3 7ES, (IK
Received 20 June 1994; revision received 2 September 1994; accepted 15 September 1994
Abstract
The national and international rates of homicide and homicide-suicide (dyadic death) have beenstudied by examination of the available literature. The rates of homicide-suicide episodes betweendifferent countries showed considerable variation, though not as great as overall homicide rates. Despite the variation the features of the episodeswere similar, with a man usually killing his spouse and/or children with a firearm. The commonest motive for killing is jealousy and/or revenge, often as the result of a breakdown in the spousal relationship. Keywords: Homicide; Suicide; Dyadic death; Spousal killing; Jealousy; Revenge; Firearms; Carbon monoxide poisoning
1. Introduction There has been increasing interest over the last few years in the phenomenon of homicide-suicide, with a number of papers reporting on these episodes. In 1983, Coid examined the published data on homicide-suicide, and proposed ‘laws’ relating to homicide-suicide and mentally abnormal homicide [ 11.The laws were as follows:
1. the higher the rate of homicide in a population, the lower the percentage of offenders who are found (a) to be mentally abnormal and (b) to have committed suicide; 2. the rate of mentally abnormal offenders and those who commit suicide appears to be the same in different countries, despite considerable differences in the overall rates of homicide; and 0379-0738/95/%09.50 0 1995 Elsevier Science Ireland Ltd. All rights reserved SSDI 0379-0738(94)01648-O
118
C. hf. Milroy/Forensic
Sci. ht. 71 (1995) 117-122
3. there is someindication that the rate of mentally abnormal offenders, and those who commit suicide, remains the same,despite a fluctuation in the overall rate over time. This paper examines the published data on homicide-suicide, updating the information available to Coid, and examines whether Coid’s laws are still applicable with respect to homicide-suicide. 2. Methods Published papers reporting the phenomenon of homicide-suicide were examined. Papers on homicide which contained information on suicide of assailants were also examined. These data were also compared with my own studies undertaken on homicide-suicide in Yorkshire and Humberside, England. Data on homicide in England and Wales was obtained from official Government publications. Other government publications were used, where obtainable. 3. Results Table 1 shows the results of the published data on homicide and homicide-suicide [2-261. For comparison, rates of homicide-suicide episodes are shown in Fig. 1. 4. Discussion The results show that there is a wide variation in the rates of homicide. There is lessvariation in the rates of homicide-suicide. With countries with a high rate of homicide the percentageof homicide-suicide is low. Therefore, the first of Coid’s laws remains true. The secondlaw holds true to a certain extent, as there is lessof a variation in rates of homicide-suicide episodes than in overall homicide rates. However, when one closely examinesthe rates, it can be seenthat there is still considerable variation between some published data, Miami having a rate eight times higher than rates in England and Wales (and Yorkshire and Humberside) over a similar period. The data from the USA, and to a lesser extent other countries, suggest that with higher homicide rates there is a higher rate of homicide-suicide. Whether this is due to higher rates of violence in those societies,or due to the easewith which the killings can be achieved, is not clear. On the whole those countries with higher rates of homicide-suicide are those in which the percentage of killing with firearms is very high. Availability of weapons may therefore be a factor. In the UK, the replacement of toxic domestic coal gas with ‘natural’ gas, which does not contain carbon monoxide, appears to be a significant reason for the low numbers of female killers in the series from Yorkshire and Humberside [19,27] compared with the study of West [15], who found 40% of killers were female, with most using carbon monoxide poisoning as the method of killing. It is more difficult to study whether the rates of homicide-suicide vary from year to year in different countries. However, the data from England and Wales supports
119
C. M. Milroy /Forensic Sci. ht. 71 (1995) 117-122
Table 1 National and international rates of homicide-suicide Country
Years
Homicide rate per looooo
Homicidesuicide (%)
Homicidesuicide rate per looooo
USA Atlanta [2] USA Washington [3] USA Miama [4] USA Houston [5] USA Los Angeles [6] USA N. Carolina [7] USA Albuquerque [8] USA Philadelphia [9] USA Kentucky [lo] Bermuda [I] Finland [ 1l] Australia [ 151 Scotland [141a Australia [IS] Hong Kong [16] Canada [ 171 New Zealand [18] England, Yorkshire & Humberside [ 191 Canada [20] England & Wales [21] Israel (Oriental Jews) [22] Denmark, Copenhagen [23] England & Wales 1211 Denmark [24] Iceland [25] Sweden [26] Israel (Western Jews) [22]
1988-1991 1974-1975 1977-1985 1969 1970-1979 1972-1977 1978-1987 1948-1952 1985-1990 1920-1979 1955-1970 1989-1991 1986-1990 1959-1960 1961-1971 1968 1976-1989 1975-1992
38.8 29.3 27.1 23.3 17.1 16.1 12 6.1 5 2.35 2.2 2 1.75 1.7 1.57 1.5 1.5 1.5
1.4 1.5 2.21 1.8 2.1 l-2 4 3.6 6 5.5 8 8 3 22 5 18 3.4 4.6
0.46 0.43 0.55 0.42 0.36 0.19 0.25 0.21 0.3 0.13 0.18 0.16 0.05 0.36 0.07 0.27 0.05 0.07
1961-1966 1980-1990 1950-1964 1968-1983 1969-1979 1946-1970 1900-1979 1970-1981 1950-1964
1.36 1.11 1.07 0.99 0.88 0.79 0.72 0.7 0.59
15.6 7.2 25.6 8 8.2 30 8.5 15.6 67.8
0.21 0.07 0.27 0.08 0.07 0.2 0.06 0.09 0.4
aExcludes Lockerbie killings. There is somediscrepancy between the rates of homicide, percentage of homicide-suicide and the rate of homicide-suicide.This is becausemost authors calculate the homicide rate from the number of victims but the homicide-suicide rate from the number of episodes.There is also some rounding up of numbers.
Coid’s third law. Since Coid published his paper in 1983 the homicide rate has increased by 20%. Despite this increase, there has been no significant change in the rate of suicide among assailants. Indeed, there has been little change in the number of assailants who commit suicide over the last 30 years, despite the annual increase in homicide [19,27]. It would be interesting to see how data from other countries compares with the data from England and Wales. In 1992,Marzuk and colleaguesproposed a classification of homicide-suicide [28]. This is shown in Table 2. The classification is based on the type of relationship between the victim and perpetrator, and based on the perpetrator. The commonest type for homicide-suicide is spousal killing, with the man killing his wife, because
120
C. hf. Milroy/Forensic
Sri. ht. 71 (1995) 117-122
INTERNATIONAL HOMICIDE - SUICIDE RATES SCOTLAND 1957-195s NEWEEALAND saYrLAND1!MI6-9o KImAND YORKSHIRE AND HUMBERSIDE U.K. HONG KONG ENGLAND AND WALES 1%9-79 ENGLAND AND WALES l!MbMO DENMARK (COPENBAGBN) 1%&83 SWEDEN
ENGIANDANDwALEs 1991 ENGLANDANDWALIBENGLAND AND WALES MS&S!3 BERMUDA AUSIRALIA l!mal FINLAND NORTH CAROLINA U.S.A.
DENMARKI~~~~ CANADA 191148 PHILADELPHIA U.S.A. ALBUQUBRQUB U.S.A. I!sRAEL (ORIENTAL JEWS) CANADA 1%6 KENTUCKY U.S.A. AU~195%0 LOS ANGELES USA. ~=vJEws) HOUSI’ON U.S.A. WASIilNCI’0NU.S.A ATLANI’AUJ3.A.
as
.l
.15
3
.25
3
35
A
A5
.!!
55
06
PER 100,000 Fig. 1. International homicide-suicide rates.
of the breakdown of the relationship with resultant jealousy and revenge. Another common type is the killing of the children by their father or mother, with an element of misplaced altruism. The father is the most common perpetrator, though West’s study found women to be the assailants who most frequently killed their children. Alcohol intoxication of the perpetrator is a significant factor. Marzuk and colleaguesrecorded that the epidemiology of homicide-suicide in England was different from other countries, based on West’s results. However, the more recent studies from England do not indicate this, and have shown similar features to other studies, with male killers forming the vast majority, their spouse the most frequent victim
C. hf. Milroy/Forensic Sci. ht. 71 (1995) 117-122
121
Table 2 Classification of homicide-suicide (Matzuk et al. [28]) Type of relationship I. Spousal or consortia1 Perpetrator (a) Spouse (b) Consort Type of homicide (i) Uxoricidal (spouse-killing) (ii) Consortia1 (killing of lover) II Familial Perpetrator (a) Mother (b) Father (c) Child (< 16 years) (d) Other family member Type of homicide (i) Neonaticide (child ~24 h) (ii) Infanticide (child > I day, < I year) (iii) Pedicide (child > I year, < I6 years) (iv) Adult family member III Extrafamilial Class A Amorous jealousy B Mercy killing C Altruistic or extended suicide D Family, financial or social stressors E Retaliation F Other G Unspecified
[19,27]. A significant subgroup of male killers will kill their entire family, so called ‘family annihilators’. Hanslick and Koponen [2] have recently proposed modifications to the classification, though the basis of the classification is the same. Other patterns seen are the killing of an invalid or ill spouse in elderly couples, the victim usually being the woman, and killing becauseof financial stress. Mental illness is a significant factor in someepisodes,with depressivedisorders the most important. Killers of strangers are a rare phenomenon, but include mass killers who kill five or more victims in one episode. Serial killers, who kill three or more people on separate occasions, do not usually commit suicide. Overall homicide-suicide episodes show similar characteristics in the majority of published series. However, there is more variation in the rate of homicide-suicide episodesthan previously reported. This may partly be accounted for by availability of methods of killing. Cultural factors may play a part, but the question then arises
122
C. M. Milroy / Forensic Sci. Ini. 71 (1995) 117-122
as to how homicide-suicide episodes with similar characteristics in terms of the reasons for killing and the participants in the episodes should have different rates. Marzuk and colleagues called for more study of this phenomenon and suggesteda multi-disciplinary approach. These episodes are of interest to all professionals engagedin the investigation of crime and death, and present great opportunities for such a multi-disciplinary study. References [I] [2] [3] [4] [5] [6] [7] [8] [9] [IO]
[I I] [12] (131 [14] [15] [16] (171 [I81 [!9] [20] [21] [22] [23] [24] [25] [26] (271 [28]
J. Coid, The epidemiology of abnormal homicide and murder followed by suicide. Psycho/. Med., 13 (1983) 855-860. R. Hanslick and M. Koponen, Murder-suicide in Fulton County, Georgia: comparison with a recent report and proposed typology. Am. J. Forensic. Med. Pathol., 15 (I 994) !68- 173. A.L. Berman, Dyadic death: murder-suicide. Suicide Life Threat. Behav., 9 (1979) 15-23. A.R. Copeland, Dyadic death - revisited. J. Forensic. Sci., 25 (1985) 181-188. H.P. Lundsgaarde, Murder in Space City, Oxford University Press, New York, 1977. N.H. Allen, Homicide followed by suicide: Los Angeles, 1970-1979. Suicide L@ Threat. Behav., 13 (1983) 155-163. S. Palmer and J.A. Humphrey, Offender-victim relationships in criminal homicide followed by offender’s suicide, North Carolina, 1972-1977. Suicide Life Threat. Behav., 10 (1980) !06- 118. M. Rosenbaum, The role of depression in couples involved in murder-suicide and homicide. Am. J. Psychiar., 147 (1990) 1036-1039. M.E. Wolfgang, An analysis of homicide-suicide. J. C/in. Exp. Psychoparhol., 19 (1958) 208-218. S. Currens, T. Fritsch, D. Jones, G. Bush, J. Vance, K. Frederich, R. Adams, M. Adkins, J. Bothe, G. Murphy, C. Webb and R. Finger, Homicide followed by suicide - Kentucky, 1985-1990. M.M. WI?., 40 (1991) 652-659. M. Virkkunen, Suicide linked to homicide. Psychiatr. Q., 48 (1974) 276-282. H. Strang, Homicides in Australia 1989-1990, Australian Institute of Criminology, Canberra, 1991. H. Strang, Homicides in Australia 1990-1991, Australian Institute of Criminology, Canbarra, 1992. Scottish Office Homicide in Scotland 1986-1990. Sfarisrical Bull. Criminal Justice series, Scottish Office, Edinburgh, 1991. D.J. West, Murder Followed by Suicide, Heinemann, London, 1965. M. Wong and K. Singer, Abnormal homicide in Hong Kong. B. J. Psychiar., 123 (1973) 295-298. C. Greenland, Evaluation of violence and dangerous behaviour associated with mental illness. Semin. Psychiar., 3 (1971) 685-687. J. Christiansen, A. Still, T.D. Koelmeyer, Homicides offenders in Auckland, New Zealand. Am. J. Forensic. Med. Pathol., 14 (1993) 65-69. C.M. Milroy, Homicide followed by suicide (dyadic death) in Yorkshire and Humberside. Med. Sci. Law, 33 (1993) 167-171. B. Schloss and N.A. Giesbrecht, Murder in Canada. A report on capital and non-capital murder statistics, Centre of Criminology, University of Toronto, Toronto, 1972. Home Office, Criminal Statistics England and Wales 1992, HMSO, London, 1993. SF. Landau, Pathologies among homicide offenders. Br. J. Criminal., 15 (1975) 157-166. P. Gottlieb, P. Kramp and G. Garbrielsen, The practice of forensic psychiatry in cases of homicide in Copenhagen, 1959 to 1983. Acra Psychiatr. Stand., 76 (1987) 514-522. J.P. Hart Hansen, Drab i Danmark. 1946-1970, Munksgaard, Copenhagen, 1974. G.H. Gudjonsson and H. Petursson, Some criminological and psychiatric aspects of homicide in Iceland. Med. Sci. Law, 22 (1982) 91-98. P. Lundqvist, Criminal homicide in Northern Sweden 1970-81: alcohol intoxication, alcohol abuse and mental disease. Inc. J. Law Psychiar., 8 (1985) 19-37. C.M. Milroy, Reasons for homicide and suicide in episodes of dyadic death in Yorkshire and Humberside. Med. Sci. Law, (in press) P. Marzuk, K. Tardiff and C.S. Hirsch, The epidemiology of murder-suicide. JAMA, 267 (1992) 3179-3183.