After reading this chapter, you should be able to:

• Outline the composition and biological function of each of blood, semen and saliva.
• Describe the presumptive tests used to determine whether a body fluid found at a crime scene is blood, semen or saliva.
• Explain the basis on which serological tests work, with particular reference to their use in various types of blood testing.
• Understand the importance of bloodstain pattern analysis in the investigation of scenes of violent crime.