This research is a qualitative art-based study exploring trauma markers found in the artwork of serial killers through the participation of licensed art therapists trained in the identification and treatment of trauma. The literature review covers a broad range of variables that influence the development of mass murderers, and how art therapy may be useful in working with serial killer populations. The study offers a unique, non-verbal exploration of the trauma experienced by serial killers through the art therapy lens. The three participants provided invaluable data through their responses to a questionnaire and creation of response art that demonstrates evidence of complex trauma, military trauma and traumatic brain injury; all of which were supported by previous research found in the literature. Themes identified through the analysis of the data included: communication, representation, chaos and violence, life and death, and illusion of power. This study demonstrates the importance of understanding serial killers’ psychological makeup, the traumas and other experiences that have profound impacts on them, and the contexts in which they develop. This may lead to a better understanding in how to look for the warning signs in their development and artwork; allowing for the potential to prevent such violent behavior with early intervention.