The Certified Criminal Investigator Body of Knowledge

0 American College of Forensic Examiners Institute

• Publisher: CRC Press
• Year: 2017
• ISBN:
  9781498782647
• Edition: 1
• Topic: Diritto
• Subtopic: Scienza forense

Criminal investigators have a long list of duties. They must identify and secure a crime scene, conduct interviews of witnesses and victims, interrogate suspects, identify and properly collect evidence, and establish and maintain a chain of custody. Once an investigation is underway, the criminal investigator must demonstrate thorough knowledge of

Section II

Crime Scenes and Evidence

Section II deals with proper protocol of investigating and searching crime scenes and dealing with victims, suspects, and witnesses on the scene. It also details the various types of evidence that might be present on a crime scene, such as physical evidence, trace evidence, DNA evidence, and digital evidence. Procedures for collecting each type of evidence are presented. See page 229 for questions reviewing the material in Section II.

Chapter 4: Crime Scene Investigation

Chapter 5: Evidence

Chapter 6: DNA Evidence

Chapter 7: Blood Spatter Pattern Analysis

Chapter 8: Postmortem Examination

Chapter 9: Computer/Digital Forensics

Chapter 4

Crime Scene Investigation

4.1 Types of Investigations

There are two types of investigations: complaint driven and intelligence driven.

4.1.1 Complaint-Driven Investigations

Complaint-driven investigations are reactive in nature and can be generated by either individuals or entities. Individual complainants can be victims of crimes, witnesses to crimes, informants, or perpetrators. Entity complainants include law enforcement agencies, healthcare institutions, or victims of property crimes. Victims of property crime are the most common type of complainant.

4.1.2 Intelligence-Driven Investigations

Intelligence-driven investigations are proactive in nature. It requires investigators to hunt out the individual aspects of the crime themselves. These crimes are often victimless and covert. Intelligence-driven investigations are often investigations over drugs, gangs, organized crime, vice, terrorism, or foreign counterintelligence. Investigators obtain information about such crimes through witnesses, informants, and assets.

4.2 Initial Response

This section details the investigator’s first actions when responding to a crime scene.

4.2.1 Note the Dispatch Information

The first step is to log the dispatch information. Investigators can get this information from the dispatcher, the person making the complaint, or their own observations. The following list details what needs to be noted:

• Address
• Date
• Parties involved
• Specific location (e.g., storefront, second-floor rear, mile marker)
• Time
• Type of call
• Type of scene (ongoing/dangerous scene or currently safe)
• Weapons involved

4.2.2 Watch Persons at the Crime Scene

The investigator’s initial observation of people at the crime scene can provide important clues to a case. The following list details what investigators should document:

• Investigator’s time of arrival
• Vehicles present—Know the make, model, color, condition, license plate number, and age of the vehicles. Descriptions should be vague if anything about the vehicle is unclear. For example, a black Nissan could be a dark blue Toyota, so a dark color compact car might be a better description. Investigators must note any vehicles leaving the scene.
• Individuals present—List and describe anyone at the scene. Descriptions should include the person’s height, weight, race, age, clothing, gender, and any distinguishing features.
• Direction of travel—Directions always should be described with terms such as north, south, east, and west. Left and right could be many directions depending on the viewer’s location, so investigators should avoid using them.

4.2.3 Assess the Crime Scene

Investigators approach a crime scene attentively and make careful observations. Upon arrival, they scan the entire area to thoroughly assess the scene. From this assessment, investigators note any possible secondary crime scenes. If there is activity other than in the main crime scene area, this may indicate a secondary crime scene. Finally, investigators scan the area for any vehicles or people who might be involved.

4.2.4 Approach the Scene Cautiously

Investigators approach the scene cautiously to ensure their own safety. This can begin before the investigator has even arrived. Investigators should use logic in how they approach the scene in their vehicles. Information known about the crime can help investigators decide how to approach. Crime scene personnel should always park with room around their vehicle in case they must make an emergency exit. If the crime is in progress, investigators should consider the noise their vehicles make. Measures may need to be taken to guard against the perpetrators hearing the investigators as they approach.

Upon arrival, investigators assess the scene for any ongoing dangerous activity. Using their senses, investigators watch out for downed power lines, dangerous animals, o...