The newspapers today are full of the horrifying story of three children who were found dead in their family home in South London on Tuesday. The children had all apparently been diagnosed with a severe genetic disorder (spinal muscular atrophy), that was likely to lead to death in early childhood. Their mother has today been charged with their murder.

There are relatively few details available at this stage, and doubtless more will emerge over coming days and months. It would be premature to comment on the specific circumstances of the case (and the family has asked the public and media to refrain from speculation). However, it is likely that as those details do emerge that commentary on the case will take up one of two themes. Some commentators will point to the enormous strain of caring for severely disabled and terminally ill children, and perhaps bemoan the lack of available supportive services. Others (perhaps with disability or with personal experience of caring for the disabled) will react with horror at the idea of a parent killing their child, and reject any attempt to use child disability as a form of excuse for the crime.

Child homicide is rare (1.5 per 100,000 school age children in the US). Yet when it occurs it usually occurs by a parent or step-parent (this is referred to as ‘filicide’). Among these cases are a significant number of deaths of children with disability. A review of 26 cases over 30 years found that most affected children were male; just over half had autism. Mothers who kill their child have been found frequently to have significant psychiatric illness including depression and psychosis. One distinguishing feature of such killings is a high rate of apparently altruistic motivation. Mothers who kill their children sometimes appear to believe that their child would be better off dead.

What should we say about cases like the New Malden deaths? Should we pay attention to the availability of medical and social support and respite care? Supportive services might be relevant to such cases in three different ways. Support is clearly important for children with significant disability or chronic illness. It can make a large difference to the quality of their daily lives. A lack of high quality palliative care services, for example, might lead to under-treatment of a child’s physical or psychological symptoms. Support is also important for families and carers of disabled children. It can provide them with the skills and equipment needed to care for their child as well as much needed respite. Finally, support might help in identifying families who are struggling to cope with their child’s care. Clearly most parents do not harm or kill their disabled children. One important question is whether we can identify and intervene in families at risk.

Is it justified to take into consideration the severity of a child’s disability in judging a parent’s extreme action? Does the child’s disability provide any form of excuse?

One point to note is that we may seek to understand a parent’s motivation, without justifying their action. The severity of a child’s condition might lead a parent to believe that continuing to live would not benefit their child, yet this does not mean that their belief is justified. In most of these cases they will be mistaken or deluded. There are situations where a child’s illness is so severe, or their life expectancy so short that medical professionals and parents are justified in not prolonging their lives. However, few if any of the reported cases of filicide fit into that category.

Some might reject sympathy for mothers who kill their disabled child because of a feeling that this devalues individuals with disability or implies that disabled individuals have lives that are not worth living. If it were regarded as a less serious offence to kill a disabled child, this might be a legitimate concern. But attempting to understand mothers who kill their children does not mean that the death of the child is any less significant. There is a difference between our assessment of the badness of a criminal act, and our assessment (and punishment) of the perpetrator. Imagine, for example, that John, who has experienced repeated physical abuse as a child, lashes out later in response to minor provocation and kills James in a brawl. We might take John’s background into account in our evaluation of his act. It might be justified for the courts to consider that in sentencing and to be more lenient. If they did so, however, that would in no way diminish the wrongness of killing James. It would not imply that James had a life of lesser value or no value.

There are important lessons to learn from tragedies like the deaths this week in London. We should seek to understand what could lead to such desperate acts, at least in part to try to prevent them occurring again.

Friedman and Resnick Child murder by mothers World Psychiatry 2007

Coorg Filicide-suicide involving children with disabilities J Child Neurology 2013