How would you define a serial killer? To law and society this definition means very different things. To society a serial killer is someone you would watch on dateline, someone who killed more than one person. Someone who has mental illness, a difference in the brain, someone who needs help. A serial killer is someone who exists in your darkest nightmares, the person you see when you can’t sleep lurking in the shadows. It’s someone your fear, someone that makes you truly believe that life may not always be what it seems.

To law the exact definition is very different. “The term ‘serial killings’ means a series of three or more killings, not less than one of which was committed within the United States, having common characteristics such as to suggest the reasonable possibility that the crimes were committed by the same actor or actors.” (FBI 2005, P. 2). When talking about a law definition you are speaking about the act of killing, the number of people who have been killed, the statistics and numbers. When talking about society’s definition of a serial killer, we see a more emotional impact, including the names of their victims or the intention behind the murder. You must be thinking, a person who can commit such a horrible crime must be different from the rest of society. But how?

In a serial killer there are evident differences in the brain, the outcome of these brain scans truly show how serial killers differ from the rest of society. In a study done by the Mayo Clinic (2019) displayed a statistic stating that, “on average an 18-percent reduction in the volume of the brain's middle frontal gyrus, and a 9 percent reduction in the volume of the orbital frontal gyrus – two sections in the brain's frontal lobe.” (P.1) University of Wisconsin School of Medicine and Public Health states, "Those two structures in the brain, which are believed to regulate emotion and social behavior, seem to not be communicating as they should." These both stating facts proving that serial killers do have a drastic brain difference. Another study completed by Indiana University (2015) showed, “ the tendency toward being callous and unemotional (CU) in children between 7 and 12 years old. Children with these traits have been shown to have a higher risk of becoming psychopaths as adults.” This study proves that you can find tendencies in young children to predict and treat an urge that they may have before they act on it. The next question would be, why do these kids have these urges?

A possible reason why a child might feel this way is a certain experience that they may have had. This could include abuse, mental illness, or even something that their parents said or did previously. A serial killer is someone who has a reason to kill whether that’s sexual motive, a vendetta, or an exposure to interparental violence which modeled that behavior for them. In fact, “ “Heyman et al. found that mothers who experienced childhood victimization and who were exposed to interparental violence were more likely to perpetrate abuse towards their own children, and that this abuse in childhood was associated with partner violence perpetration in adulthood.”( NCBI 2013, P.2 ) As said by Medical Daily, “ “The brain's development may be impacted greatly by positive or negative experiences during childhood. A traumatic or difficult childhood could alter how the brain develops and affect certain functions. The difficult childhood could cause a child to take more impulsive risks and possibly increase the risk of mental health problems and behavioral issues. New studies are urging the legal system to take into consideration how the brain develops in response to this difficult upbringing.” (P. 1)

Mental illness is a very large problem for society as a whole, but it can also coax serial killers to commit gruesome crimes. As an example David Berkowitz, also known as ‘Son of Sam’ was arrested in 1977. He was working as a postal employee, but he was known as the man who had terrorized New York City for over a year with six casualities to his name. When he was questioned by detectives, he told them that it was demons that originated from his neighbors black labrador retriever, Sam, had convinced him to kill all six women. Hatred and anger did not originate from this dog, in fact it starts in his childhood. David was an antisocial boy, but at a very young age his mother died of cancer, leaving him to his adoptive father. When David’s adoptive father remarried and moved to Florida David decided to join the army. After three years in the army David was frustrated and carried a lot of anger towards women. While in the army, David had relations with a prostitute and contracted a disease to show for it, thus beginning his angers. After coming home he was diagnosed with paranoid schizophrenia as shown by the auditory hallucinations, and the voices he heard coming from the demons in his neighbors dogs ordering him to kill these specific women. Mental illness is something that affects many, but some killers make the decision for themselves.

David Berkowitz is not the first killer, and was certainly not the last. In fact the first noted serial killer dates all the way back to 1870’s, H.H. Holmes sometimes reffered to as ‘ Beast of Chicago’. He tortured and killed somewhere between 20 and 200 people through his con man ways. The latest serial killer was a 35 year old Army captain, although his name has not yet been released. His story was updated on ABC News on May 5th, when an article was published concerning his victims bodies being found in cryprus lake located near Ontario, Canada. He has confessed to killing 5 women and two girls, all in the span of about 2 and a half years. Although these killers may not be well known, it is important to know that these were people who needed help and never recieved it. H.H. Holmes was a con man and sought death, and this 35 year old Army captain was most likely angry or suffered from PTSD. As a world we must be aware that these were the first and last serial murders, but the hunger for killing has not been fully fed.

After looking at this existing research, I’ve come to a conclusion. Serial killers is a broad term, not defining one person or one characteristic. In fact, through this research I have found the many different definitions for this term, serial killer. Throughout the research process I realized that we musn’t close our minds to these definitions, and open our eyes to the possibility of even more definitions.

Minh, A., Matheson, F. I., Daoud, N., Hamilton-Wright, S., Pedersen, C., Borenstein, H., & O'Campo, P. (2013, October 28). Linking childhood and adult criminality: Using a life course framework to examine childhood abuse and neglect, substance use and adult partner violence.

Moskowitz, C. (2011, March 04). Criminal Minds Are Different From Yours, Brain Scans Reveal.

Poladian, C. (2012, June 18). A Troubled Childhood, A Troubled Brain, How New Research May Affect Criminal Law. 

SiOWfa16: Science in Our World: Certainty and Controversy. (n.d.).