ABSTRACT
The purpose of this chapter is to present the background of homicide in the United States, how it has been identified and recorded, and the emergent basis for practical unsolved homicide investigation. In addition, this chapter will also review trends and patterns of twentieth-century homicides in the United States, and how these affect the investigations and operations of homicide investigators assigned to investigate unsolved, cold case homicides in the twenty-first century. This chapter will review homicide and homicide data to identify the scope of unsolved murders in the United States at this time, and will review trends and advances in the forensic sciences and their application to cold case homicide investigation. The chapter will conclude by reviewing circumstances that contribute to cases growing cold and to recent trends to reinvestigate such cold cases.
