Key points
- Convicted killers like Bryan Kohberger are human beings with severe psychiatric problems.
- If we wish to better comprehend the evil deeds of such criminals, it is essential to study their psychology.
- Not every person who commits such horrific crimes is necessarily a psychopath or sociopath.
What compels accused or convicted murderers like Bryan Kohberger, Lindsay Clancy, Luigi Mangione, and Tyler Robinson to kill? Are there any commonalities that can help us to better comprehend their evil deeds? In this part (Part 1) of a series on criminal forensic psychology, let us begin with the deeply disturbing case of Bryan Kohberger
Mr. Kohberger, a former doctoral student in criminal justice, is currently serving four consecutive life sentences in a maximum security prison after pleading guilty to and being convicted of the horrific killings of four students from the University of Idaho in 2022. (See my prior post.) However, he is now again claiming to be innocent of these murders and seeks to formally withdraw his original 2025 guilty plea claiming it was made under duress and with incompetent legal counsel
While this appeal, according to legal experts, is highly unlikely to succeed, there is now some information available regarding his psychiatric or mental health history that could shed more light on what might have motivated these extremely evil deeds, thanks to a recently unsealed neuropsychological evaluation conducted for the defense team, which reportedly stated that Kohberger was diagnosed with autism spectrum disorder, OCD, DCD (developmental coordination disorder, typically associated with ASD), ADHD, ARFIC (avoidant/restrictive food intake disorder sometimes associated with anxiety disorders, autism, schizophrenia, and other eating disorders), anorexia nervosa, unspecified depressive disorder, and opioid use disorder now in sustained remission.
I have never personally evaluated nor met Mr. Kohberger, and cannot ethically diagnose him without having done so. But, as a practicing forensic psychologist with extensive experience working with both the criminal and civil courts in California, reading this long laundry list of psychiatric diagnoses, when added to what we already knew about him, paints a clinical picture of someone who has suffered most of their life from severe and chronic anxiety, obsessive-compulsive symptoms, chronic depression including extremely low self-esteem compensated for by narcissisticdefense mechanisms, and, based on the method and description of the overkill at the bloody murder scene, immense but mostly repressed or unconsciousanger, rage, resentment, and embitterment or what one might generically refer to as an “anger disorder.”
Here, as in similar cases I have seen over the years, the presence of the repressed anger or rage may be key, since it drives and motivates such ultra-violent behavior. Frequently, the anxiety symptoms, including obsessive-compulsive disorder (which is an anxiety disorder by definition), and depression, can be the consequence of chronic repression of the rage or what I call the daimonic. (See Diamond, 1996; 2025.)
Substance abuse is commonly used by such individuals as a form of self-medication for suppressing and keeping the feelings of anxiety, anger, rage, and depression at bay. Severe and chronic anxiety (and/or depression) can also play a significant and exacerbating role in disorders such as ADHD and mild autism spectrum insofar as they can cause social and cognitive impairment in general, and more specifically, serious deficits in one’s capacity to focus, concentrate, and recall information and events, both recent and remote. Sometimes, transient or chronic psychotic symptoms such as command hallucinations or paranoid delusions may be present, though there are, at least thus far, no prior indications of this in the Kohberger case.
However, it has become more clear now, according to this latest report, that Mr. Kohberger suffers from not only some neurological but also severe psychological and emotional problems. But from whence did they spring? Sexual frustration? (Some speculate he was a so-called incel, like mass shooter Elliot Rodger.) Social rejection? Having been bullied as a boy for being morbidly obese or because of his psychiatric symptoms by his peers? Dysfunctional family dynamics? Or, was he simply born this way?
What is conspicuously missing thus far to my knowledge is any meaningful information on Kohberger’s family and particularly his relationship with his parents. This, psychologically speaking, is where at least some of the kinds of problems from which he seemingly suffers usually start. (It has been reported that he called his parents, and particularly his mother, repeatedly right after the murders, suggesting some special closeness, connection, or dependency.)
Assuming, for example, that he is indeed a very angry guy, what made Kohberger so mad — mad or enraged enough to kill, no, butcher, four innocent college kids? What happened to him earlier in life? Why was his supposed autism not diagnosed and treated sooner, as these symptoms are usually evident by age 2? He reportedly has two sisters: How did they fare in the family system and how are they functioning now?
Forensic Psychology Essential Reads
Lindsay Clancy’s Trial: What Will Sway the Jurors?
When Depression Enters the Courtroom
How did he feel toward them? (Bizarrely, it seems that one older sister, a former actress, appeared some 15 years ago, while Bryan was still in his teens, in a low-budget slasher film about someone slaughtering young college students. Coincidence?) These unanswered questions are not at all a matter of trying to blame Bryan Kohberger’s parents or family for what he did, since that was solely his own responsibility. But answers are essential in better understanding how he went on to become the murderous person he did.
From a strictly diagnostic standpoint, I believe the crucial remaining question for the forensic mental health professionals involved in this case has to do with whether Mr. Kohberger manifests some kind of previously undiagnosed personality disorder, an overarching character structure that unites his seemingly disparate symptoms into some more or less cohesive and enduring pattern of experience and behavior. Based on the limited collateral information publicly available, and my previous clinical experience, I suspect that he may.
The most likely diagnosis in tragic cases such as this usually would be antisocial personality disorder or psychopathy. (See Diamond, 2022.) However, to diagnose APD specifically, there must be documented evidence of “a pervasive pattern of disregard for and violation of the rights of others, occurring since age 15 … [and] … of conduct disorder with onset before age 15″ (DSM-5-TR). Based on what we, the public, currently know about Kohberger’s history, maybe or maybe not
Perhaps surprisingly to some, the diagnosis of APD cannot be made simply based on the nature of the evil, heinous, and sadisticcrime itself. One need not necessarily be a psychopath or antisocial personality to commit such a violent offense. For instance, horrifying crimes of passion can sometimes be committed by people without any history of antisocial traits. The terrifying fact is that every human being has the capacity for evil, though it is far more comforting to convince ourselves that only some minuscule percentage of the population (an estimated 1%-4% are psychopaths or sociopaths) could conceivably be capable of doing something so exceptionally evil, cruel, and brutal.
So, at this point, more data would be needed before reaching a specific personality disorder diagnosis, though there may, in my view, be sufficient information right now to support the presence in cases such as this of some type of character disorder (e.g., general personality disorder with antisocial traits). If so, such a diagnosis made by the forensic clinicians involved could help us to make a little more sense of who this individual is and why he did what he did
Diamond, S.A. (1996). Anger, madness, and the daimonic. SUNY Press
Diamond, S.A. (2025). The psychology and psychotherapy of evil: Encountering the daimonic. In Hoffman, L. (Ed.), The APA handbook of humanistic and existential psychology. Vol. 1. APA Press
APA. (2022). DSM-5-TR. American Psychiatric Association
