Steps to conducting a criminal investigation include arriving at the crime scene, documenting the crime scene, processing the scene, and completing and recording the crime scene investigation, explains the National Institute of Justice. Once the scene is thoroughly investigated, the pre-arrest investigation takes place, which includes identifying a suspect and either involving a prosecuting attorney or determining if there is insufficient evidence, thereby dropping the case, the National Crime Victim Law Institute asserts.
Upon arriving at the crime scene, a first responder must determine what medical assistance is needed, confirm or pronounce a death if one exists, and conduct an analysis of the area, according to Forensics Talk. After determining the lead investigator, she must preserve the crime scene, which involves barricading or roping off the area and preventing unauthorized people from entering the scene. Since anyone who enters the crime scene has the potential to contaminate it, access must be limited.
Before anything is touched, photographs must be taken, states Forensics Talk. There needs to be pictures of the overall scene, as well as at least one photo of every item significant to the crime. Overview, mid-range and close-up photos are needed. Rough sketches and finished sketches with accompanying notes also are obtained.
The lead investigator conducts a thorough search of the area. Collecting evidence is imperative to the success of the investigation and must adhere to a variety of regulations, notes Forensics Talk.