The case this data is taken from is a 2021 study, entitled '
Personality Disorder Traits, Rorschach
Performance, and Neuropsychological Functioning
in the Case of a Serial Killer: The Importance
of a Multilevel Approach in the Assessment
of Personalities Associated with Extreme and
The subject of this study was an incarcerated serial killer "Keith" is the pseudonym used within the study.
The paper is at the end of my brief summary.
Keith was raised by his biological parents, and while Keith described his father as a good provider, he also described his father as a drunk with "severe mood swings". The parents were distant from their son and Keith himself was also distant from his two brothers and two sisters. There was a history of physical abuse by both his parents towards him.
Keith had a history of teenage binge drinking.
Keith's criminal history includes a confession of the murder of eight women and generally took place within the truck he drove he work. The chief method was by means of manual strangulation.
The broad classification of the crimes was deemed sexual in nature, and the victims included sex workers as well as one long-term girlfriend.
Personality traits discovered
Using the SCID II (Standard Clinical Interview), Keith was found to have
"...four of the five narcissistic personality disorder criteria (grandiosity, entitlement, lack of empathy, and arrogance/haughtiness"
Keith also displayed three of five borderline personality disorder criteria including:
Unstable and intense interpersonal relationships
The neuropsychological findings showed no damage to the frontal lobe areas responsible for executive functions such as decision making. Intelligence was roughly low to average with lower verbal skills.
I could only briefly mention some findings of the paper, but it's a very interesting look behind the sort of assessment given to serial killers and yields some fascinating data. It's also highly accessible.
The paper can be found here: https://www.tandfonline.com/doi/pdf/10.1080/00223891.2021.1942023