Crime reconstruction is the determination of the actions and events surrounding the commission of a crime. It requires use of the scientific method, that is, state a hypothesis, then examine the hypothesis in a deliberate effort to prove yourself wrong. In this manner, you arrive at the correct conclusion.

A reconstruction may be accomplished by using the statements of witnesses, the confession of a suspect, victim statements, or the examination and interpretation of physical evidence. Collectively, these investigative components may enable the investigator to accurately infer certain characteristics of the offender, and assist in accurate resolution of the investigation. 

This should not be confused with Crime Scene Reconstruction, which is the documenting of the physical aspects of the scene, or Crime Scene Processing, popularly referred to as CSI, which is the identifying and seizing physical evidence at a crime scene.