Raising Cain: The Problem of Family Homicides

August 22, 2016

Individuals with serious mental illness are responsible for more than 7% of the nation’s homicides. What can be done to reduce this deadly phenomenon?

Since Cain and Abel are depicted in the Bible as the first children of Adam and Eve, the killing of Abel by his brother can be said to have been the first homicide. Ever since, family homicides have infused the mythology of many cultures, including the work of Sigmund Freud in our own. Despite this, psychiatric aspects of family homicides have been inexplicably ignored. As Labrum and Solomon1 recently noted, “family violence perpetrated by persons with psychiatric disorders is a highly under-researched area, so much so that it is impossible to even approximately estimate the extent of the problem.” And among families of individuals with a serious mental illness the subject is rarely discussed, compared by one woman to “living in a closet within a closet.”2

To assess the magnitude of this problem, the Treatment Advocacy Center undertook a study of family homicides. We utilized the FBI’s Supplementary Homicide Reports (SHR), a sampling of all homicides in the US; it is the only national database with information on the family relationship of offenders and victims. We supplemented this by collecting all 2015 media accounts of family homicides in which the offender was identified as having a serious mental illness. Finally, we reviewed the psychiatric literature, which is remarkably sparse in American studies, for estimates of the prevalence of serious mental illness among the perpetrators of family homicides.

Magnitude of family homicides

According to the CDC’s National Vital Statistics System, there were 16,121 total homicides in the United States in 2013. Data from the FBI’s SHR sample suggests that 25% of these, or approximately 4000 homicides, were homicides in which one family member killed another. The largest number of these were spouse on spouse homicides (1433), followed by parents killing children (908); children killing parents (649); siblings killing siblings (301); and other family combinations (589).

A review of the existing psychiatric literature on each of these types of family homicides revealed major differences. Serious mental illness is estimated to play a major role in only 10% of spouse homicides; the majority are driven by infidelity, jealousy, alcohol, and other factors. By contrast, serious mental illness is estimated to play a major role in 67% of homicides in which children kill parents and 50% of homicides in which parents kill children. When such calculations are made for each type of family homicide and totaled, the number of family homicides associated with serious mental illness is approximately 1150. This is 29% of all family homicides and 7% of all homicides in the US.

Several aspects of these family homicides are of special interest. Although total homicides in the US have decreased progressively in recent years, there has been no decrease in the number of parents killing children or children killing parents, the 2 types of homicides strongly associated with mental illness. The weapons used were also somewhat surprising. In our media sample of family homicides associated with serious mental illness, guns and knives or other sharp objects were used equally-but each in less than one-third of homicides. Fatal beatings comprised the majority of the others, especially when the victims were very young or elderly. The beatings were done with fists but also with a variety of objects including baseball bats, golf clubs, hammers, and a tea kettle.

One of the most striking findings from this study was the number of elderly victims. Among all homicides in the US, only 5.1% of victims were age 65 or over and 2.2% were age 75 or over. By contrast, among our media sample, 17.7% of the victims were 65 or older and 9.2% were 75 or older. Thus, elderly parents and grandparents appear to be especially vulnerable victims in family homicides. This is presumably another result of the emptying of state psychiatric hospitals with the former patients forced to live with their families. In a small number of cases, this turns out tragically.

The failure to take prescribed psychiatric medication played a major role in family homicides in our study. In the vast majority of cases in which such information was available, the offender was noted to be not taking medication. This result is consistent with the literature. For example, a study of family violence found “compliance with medication” to be the most important variable that discriminated violent from nonviolent mentally ill relatives.3 Co-occurring substance abuse, especially alcohol abuse, in conjunction with serious mental illness also plays a major role in family homicides. In a study of family homicides by the Department of Justice, in 64% of cases the offender was using alcohol at the time of the killing.4

The majority of family homicides are preceded by warnings and threats that are often ignored. In a study of parents who killed their children, “three-quarters of the parents showed psychotic symptoms prior to their filicide. Some mothers talked openly of suicide and even expressed concern about the future of their children.”5 In another study of 43 children who killed their mothers, “warnings of intended homicides or previous attacks on the mothers were identified in 24 cases.”6



The fact that individuals with serious mental illness are responsible for more than 1100 family homicides each year-7% of the nation’s homicides-suggests that there is a serious problem. What can be done to decrease these numbers and reduce this deadly phenomenon? The following 6 recommendations would significantly improve the situation if implemented.

1) Provide adequate psychiatric treatment. The linchpin for reducing the numbers of family homicides associated with serious mental illness is to provide adequate psychiatric treatment, especially for individuals who have risk factors that make it more likely that they will commit violent acts. Clozapine, the one antipsychotic demonstrated to decrease aggression and violent behavior in individuals with serious mental illness, is woefully underutilized by psychiatrists in the US.

2) Ensure that the prescribed antipsychotic medication is actually taken. A Swedish study of family homicides found that 48% of the mentally ill offenders had been prescribed antipsychotic medication, but only 4% of them were actually taking the medication.7 An obvious solution to the nonadherence problem is to switch the individual from oral medication to long-acting injectable preparations, which are now available for 6 antipsychotics.

3) Use assisted outpatient treatment. An individual with multiple risk factors for violent behavior against family members or a history of such behavior is an ideal candidate for assisted outpatient treatment (AOT). AOT requires the individual to be compliant with his or her prescribed treatment plan, including medication, as a condition for living in the community. AOT is available by law in all states except Massachusetts, Connecticut, Maryland, and Tennessee, but it is underutilized in most of the states where it is available. In a randomized trial in North Carolina, subjects with a history of serious violence had a reduction in violence from 42% to 27% when AOT was continued for at least 6 months.8 In New York, AOT reduced the proportion of individuals who “physically harmed others” from 15% to 8%, and the proportion who “threatened physical harm” from 28% to 16%.9

4) Reform the federal HIPAA regulations. The federal Health Insurance Portability and Accountability Act (HIPAA) was passed by Congress in 1996 in an effort to safeguard the privacy of patients’ medical records. Unfortunately, it has been widely over-interpreted to severely restrict family access to basic medical information regarding family members over the age of 18. This has been especially problematic for those with a seriously mentally ill relative living with them, who often are not given basic information such as the person’s diagnosis or list of prescribed medication.

5) Focus on the individuals with the most risk factors. As noted previously, in the majority of cases of family homicides the offender has given clear warning signs. For example, in the review by Hillbrand and colleagues10 of 237 individuals who had killed their parents, “threats of harm and assaultiveness toward the victim prior to the crime were reported in most studies.” Too often, state laws regarding the involuntary commitment and treatment of psychiatric patients are interpreted very narrowly, with families being told, “We can’t do anything until he or she demonstrates dangerousness.”

6) Improve data collection and research. Given the magnitude of the family homicide problem and the fact that a subset of these homicides is preventable by treating the offenders’ mental illness, this would appear to be a promising area for better data collection and research. For example, better data should be collected on non-lethal assaults carried out by family members with a serious mental illness. Completed homicides are merely the tip of the iceberg. Longitudinal studies should also be done to assess possible relationships between family homicides and indicators of treatment availability, such as the number of available psychiatric beds.


In addition to saving lives, there is another important reason to try to decrease family homicides. A national survey reported that news stories about violent acts by mentally ill individuals “appear to play a critical role in influencing negative attitudes towards persons with serious mental illness.”11 Such negative public attitudes are at the core of stigma that affects all persons with any mental illness, making it more difficult for them to socialize, find employment, or obtain housing. Stigma against people with mental illness will not decrease until we decrease the number of mentally ill individuals who commit violent acts, including family homicides. And that will happen only when we begin to provide better treatment.



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One of my most important life experiences was the 2 years I spent in Ethiopia as a Peace Corps physician. We had over 600 Peace Corps volunteers, mostly teachers, in the country at the time, and it was very rewarding to help move the country into the 20th century. My job included activities such as treating hepatitis in a volunteer and the consequences of a lion encounter in a Somali boy, and organizing a health education program for television-sometimes all on the same day. I return to Ethiopia regularly, and my wife and I are sponsoring a program for girls’ education in the economically poor southern region, where most girls go only to primary school. Currently, there are 130 girls in secondary school and university in the program. We are sponsoring a similar program in rural Tanzania in an area where my wife was a Peace Corps volunteer.

I also enjoy sports, classical music, and movies. I played competitive ice hockey, including organizing it as a club sport at Stanford, until age 61, when the warranty on my original hips expired. My wife and I regularly go to mostly baroque concerts and the opera, and this fall we will be returning to Italy for another Verdi opera tour. We also go to movies frequently. My all-time favorites are the classics of Ingmar Bergman, but recent movies I would recommend include Weiner (especially for psychiatrists) and Eye in the Sky.


Dr. Torrey is a Research Psychiatrist who specializes in schizophrenia and bipolar disorder. He is founder of the Treatment Advocacy Center and Associate Director of the Stanley Medical Research Institute, which supports research on schizophrenia and bipolar disorder, and he is Professor of Psychiatry at the Uniformed Services University of the Health Sciences in Bethesda, MD. He reports no conflicts of interest concerning the subject matter of this article.


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2. Anonymous. Letter to National Alliance on Mental Illness of Massachusetts. February 7, 1992.

3. Swan RW, Lavitt M. Patterns of adjustment to violence in families of the mentally ill. J Interpers Violence. 1988;3:42-54.

4. Dawson JM, Langan PA. Murder in Families. Special Report NCJ 143498. Washington, DC: Bureau of Justice Statistics.1994:3-38.

5. Resnick PJ. Child murder by parents: a psychiatric review of filicide. Am J Psychiatry. 1969;126:325-334.

6. Green CM. Matricide by sons. Med Sci Law. 1981; 21:207-214.

7. Nordstrom A, Dahlgren L, Kullgren G. Victim relations and factors triggering homicides committed by offenders with schizophrenia. J Foren Psychiatry Psychol. 2006;17:192-203.

8. Swanson JW, Swartz MS, Borum R. Involuntary out-patient commitment and reduction of violent behavior in persons with severe mental illness. Br J Psychiatry. 2000;176:224-231.

9.Kendra’s Law: Final Report on the Status of Assisted Outpatient Treatment. Albany, NY: New York State Office of Mental Health. March 2005.

10. Hillbrand M, Cipriano T. Commentary: parricides-unanswered questions, methodological obstacles, and legal considerations. J Am Acad Psychiatry Law. 2007;35:313-316.

11. McGinty MS, Webster DW, Barry CL. Effects of news media messages about mass shootings on attitudes toward persons with serious mental illness and public support for gun control policies. Am J Psychiatry. 2013;170:494-501.