WHAT creates a serial killer?

It’s a question that has long interested crime investigators and forensic psychologists alike. 

In the 1970s, criminal profiling was pioneered by FBI agents John E. Douglas and Robert K. Ressler, along with psychiatrist Dr. Ann Burgess, through the Behavioral Science Unit (BSU) at Quantico, Virginia. Their aim was to better understand the minds of violent offenders and respond to the growing number of serial killings emerging during that decade.

They wanted to create a process that can help law enforcement identify the modus operandi of serial killers, narrow down suspects more efficiently, and, most importantly, understand the psychology behind these crimes. 

This last objective was especially crucial, as it offered the potential not only to prevent future killings but also to recognize and address the factors that could contribute to the making of a serial killer.

The 1970s and 1980s, in particular, saw an alarming surge in serial killings— a period some, with a touch of dark humor, have dubbed the “Golden Age of Serial Killers.” 

Notorious figures like Ted Bundy, John Wayne Gacy, Gary Ridgway, and Richard Ramirez emerged during this era, dominating headlines and instilling widespread fear across the United States.

But why did it happen? Why did serial killers seem to erupt out of nowhere during this time period haunting the suburbs, terrorizing the co-eds, and wreaking havoc in sleepy towns? What makes the 70s and 80s different from the eras that came before and after? 

Some theories and their criticisms

Many theories have been spawned as to answer why a lot of serial killers emerged during the 70s and 80s. 

In General Strain Theory, Criminologist Robert Agnew forwarded the idea that social upheavals, including economic instability, racial tension, and gender inequality can cause individuals to become more violent, thus, creating serial killers. 

On the other hand, Routine Activity Theory by Cohen and Felson argued that it was because many easy victims— such as women and children— began frequenting the public spaces alone, increasing the target pool for the predators. 

Then there was also the theory that pointed to the war trauma and intergenerational effects of the previous wars. Historians like Peter Vronksy argue that serial killers from the 70s and 80s were children of WWII or Vietnam War veterans. 

Many of these vets returned with Post Traumatic Stressed Disorder (PSTD) that might have led to the creation of chaotic and abusive households that may have bred trauma, neglect, and violence in their children. These kids soon grew up with their own trauma manifested in their aggression and violence, leading them to become serial killers. 

While each of the theories have their own merits, they were also plagued with criticisms. 

Both the social strain and routine activity shift theories, for instance, have been criticized for placing too much weight on social conditions while overlooking psychological and neurological predispositions. 

While it’s true that societal pressures and disruptions can lead to increased crime rates, these theories fall short in explaining a crucial point: if so many people experience the same social strains, why do only a few become serial killers? 

Meanwhile, the war and intergenerational trauma theory lacks strong empirical backing. Many children of war vets didn’t become violent, let alone serial killers. 

Like the criticism against the previous two theories, many pointed out that this suggestion tends to generalize an entire generation while ignoring individual predispositions. Critics even argue that this assumption can be prejudiced as it unfairly pathologizes war veterans. 

Murderland and the environmental theory

It is frustrating to comb through theories and only face a dead-end as to what really contributed to the surge of serial killers in the 70s and 80s era. As long as the question remains unanswered, there will always be the risk of repeating history. 

This was exactly how American author and environmental historian Caroline Fraser felt. Having come of age during that era, she couldn’t shake the sense that an answer was buried somewhere beneath the fear and chaos. That there had to be a reason.

A part of the pattern has already emerged— it happened in the 70s and 80s. Another clue was most of the serial killers were from the Pacific Northwest. 

But what exactly was happening during this time that contributed to the rise of violence and aggression? What was in the air of the Pacific Northwest that created these monsters?

To answer these, Fraser turned to investigate what she calls the “lead-crime hypothesis,” a theory that first made its round among academics before entering the mainstream in the 2010s. 

In this theory, Fraser looked beyond the usual criminal, psychological, and neurological angles—she also turned to the environment, searching for clues in the world she and these killers grew up in.

In her book Murderland: Crime and Bloodlust in the Time of Serial Killers, Fraser points to what she believes is the real culprit: the toxic chemicals released by factories located near the neighborhoods where many of these serial killers grew up.

This marked one of the most in-depth and thorough explorations of the “lead-crime hypothesis.” While unconventional, Fraser’s take carried significant weight. 

In the ’70s and ’80s, industrial smelters were especially common in the Pacific Northwest—facilities used to extract metals like iron, copper, lead, aluminum, and zinc from raw ore. 

But along with production came pollution. 

These plants released toxic chemicals, including lead, into the surrounding environment, contaminating the air. It eventually led to the passage of the Clean Air Act in 1963 and the Environmental Protection Agency in 1970 but some continued with their ways and created more damage to the air quality. 

Fraser’s argument throughout the book is backed by extensive research, data, and detailed analysis. At first, the idea may seem far-fetched—but as she lays out her evidence, the connection between nature and nurture becomes increasingly difficult to ignore. 

Her work suggests that environmental exposure, particularly to toxins like lead, may have played a far greater role in shaping violent behavior than previously believed.

A new perspective

Fraser’s theory doesn’t just offer a new angle on an old mystery. It opens up a whole new perspective in how we understand the roots of violence. 

If environmental toxins like lead have a subtle yet profound effect on our brain development and impulse control, then the creation of a serial killer isn’t just about a question of trauma or personality, but one of environment, policy, and exposure. 

This implies that the consequences of environmental abuse aren’t limited to natural disasters, rising area levels, or polluted rivers. It positions environmental neglect not just as an ecological crisis but as a social one. 

It reminds us that a crime against our environment isn’t just a crime against nature—it’s a crime against ourselves.