This chapter examines the history and changing definitions of aggression, violence, and homicide, particularly as it relates to the United States. What constitutes violence and aggression, and specifically homicide, continues to evolve. Distinctions between homicide, murder, and manslaughter are clearly delineated. Additionally, novel loopholes and other legal quandaries are investigated. The chapter presents a lengthy history of homicide as far back as the 21st century
bce
through the modern day to demonstrate the changing sentences and definitions that have existed throughout civilized human history. Modern‐day homicide statistics, trends, patterns, and rates are also analyzed and discussed at length; these include an in‐depth examination of race, gender, age, and ethnicity as they relate to perpetrators and victims, as well as geography and how each of these factors relates to murder. The analysis concludes with an attempt to correct the general misperception that serial killing and mass murder are rampant throughout American society.