Contemporary neurocriminological research reveals that while no single ”murder gene” exists, specific genetic variants—most notably the MAOA-L allele and CDH13 gene—are significantly associated with increased susceptibility to violent and antisocial behavior. These genetic predispositions become activated primarily through environmental stressors, particularly childhood abuse and trauma. Meta-analyses of behavioral genetics studies demonstrate that approximately 40-60% of variance in antisocial behavior is attributable to genetic influences, while gene-environment interactions provide the most robust predictive framework for understanding extreme criminal behavior. Historical legal defenses have invoked genetic causation for homicide with mixed outcomes, but scientific consensus maintains that genetic predisposition alone does not deterministically produce killers. The interplay between genetic vulnerability and environmental indoctrination through trauma, abuse, and adverse childhood experiences remains the most accurate model for understanding the etiology of violent criminal behavior, including serial killing.