This post I write to inspire readers to find real-life crime case studies where a crime has been committed due to neurological dysfunction.
I'll start this off with an example: I've posted the link to this case study at the bottom of the post but a WARNING: The case study from the journal includes graphic crime-scene photography to illustrate the case.
I will summarise the case so that the reader does not need to click and read the case study contained within the journal unless they are prepared to see crime-scene photography.
With that warning issued let's press on to a fascinating case.
Psychiatric history
This case study involves an 83-year old man who was killed by his unmarried son aged 45.
The psychiatric history of the murderer involves the following:
An initial diagnosis of bipolar disorder following several profound delusions
12 years before the crime took place a diagnosis of depression and personality disorder
Post Homicide diagnoses:
Schizoaffective disorder
Acute paranoid delusion
This is where the story gets rather strange - it is the nature of the delusion which captures the minds of authors such as I.
And it is to this delusion that we turn to next.
Imposters and Capgras Delusion
Capgras delusion, in brief, is the delusion that a member or members of one's family has been replaced by malevolent forces such as imposters. First described in 1923 by Joseph Capgras the condition is similar to 'face blindness' or prosopagnosia in which people do not recognize people they know well and have to rely on cues such as spectacles, facial hair, etc
Prior to work by Ramachandran and other neurologists, the causes for delusions such as those caused by Capgras were explained via Freudian concepts. However, the neuroanatomical realizations of the following work by modern investigators reveal a disconnect between emotional networks within the brain and the occipital regions that maintain the function of sight. What this in essence means, is that upon viewing a member of their family, the patient does not attribute the family member with any emotional impact.
Without this emotional impact - the brain struggles to reconcile this fact and explains it away by postulating the presence of imposters who only look and sound like the people the patient recognizes.
The evidence of the emotional centers of the brain and the occipital region has been verified in laboratory settings with actual participants whose galvanic skin responses were measured as they saw generic images and pictures of family members.
Back to the case!
Without wishing to go into too much detail about the injuries sustained, a variety of implements were used - so much so that overkill was achieved. Following the murder, the victim's son phoned his "his sister and brother-in-law to reassure them that “everything had been fixed”. He then rang the neighbor’s doorbell, but they did not open the door, so he remained in a state of perplexity on their stairs with a tattered towel in his hands."
The patient also affirmed to authorities his belief that "...that he killed his father because he had been replaced by an impostor that threatened both his father’s and his own life. He also reported that at times he perceived the impostor as an inanimate object, such as a “sack of potatoes”."
The expert, in this case, concluded that the perpetrator should not be held responsible for the crime as he was in a profound delusional state.
Conclusion
Case studies like this point out the delicate line of sanity that we must all walk every day. A delusional state such as Capgras delusion may follow a dementia diagnosis such as Alzheimer's and although it is rare needs to be considered.
The mind creates reality and if the mind is afflicted by delusions - this can be troubling for jurisprudential considerations.
Feel free to add your own case studies in the comments
Here is the link to the paper in which this case features: WARNING: I post this warning again - please be aware that this paper features graphic crime-scene photography
https://link.springer.com/article/10.1007/s12024-020-00314-4
Other links for further info on Capgras:
https://www.sciencedirect.com/topics/neuroscience/capgras-delusion
Dan Sumner