This document summarizes research on the causes of serial killing. While some studies have correlated serial murder with childhood abuse or brain deficiencies, the document notes that not all serial killers experience these factors. It discusses research finding both genetic and environmental influences, with diminished brain activity found in certain regions of serial killers' brains. The document concludes that combining biological and psychosocial theories is needed to understand what provokes serial killing and that early signs like animal torture should be addressed with therapy or removing children from abusive homes, despite challenges, in order to prevent future serial murders.