The significant decline in murder rates from the early 1990s to 2019 in places like New York City, alongside similar trends in Medellin and El Salvador, highlights the complex interplay of factors influencing violent crime. In El Salvador, enhanced enforcement methods, including mass incarcerations under emergency legislation, led to drastic decreases in murder rates, raising questions about the balance between individual rights and public safety. The decline in violent crime is not solely attributable to policing strategies; it is part of a broader context that includes factors like the removal of lead from gasoline and paint, which has been linked to reductions in ADHD and violent behavior. Various studies suggest a correlation between lead exposure and increases in violent crime, indicating that public health measures can significantly affect crime rates. Additionally, issues like the socio-economic context and landmark legal decisions, such as Roe v. Wade, contribute to discussions about causality in crime rate fluctuations. The evidence suggests that while policing practices play a role, multiple overlapping factors must be considered to understand the complexities of crime rate changes.