Criminal Justice: CRJU 1072 Introduction to Forensic Science

Forensic Science

Introduction of forensic science covers basic topics such as what forensic science is, types of evidence and collecting, forensic specialties, and the value of forensic science in the criminal justice system.

At the end of your course you should gain knowledge about the following topics:

Introduction to Forensic science

Physical evidence and legal system

Crime scene Procedures, techniques, and analysis

Physical pattern Evidence and technological Examinations

Fingerprints

Toolmarks and firearms

Documents

Biological evidence

Chemical and material evidence

Arson and explosives

Drug and drug analysis

Forensic specialties

Forensic Science is science that is applied to legal problems like criminal cases. Forensic science main purpose is to establish elements of a crime or Corpus Delicti. Forensic science is also used to identify substances or materials, identify persons, provide investigative leads, and establish linkage or exclusions of evidence. 

Steps of the Scientific Method:

Careful Observation 

Hypothesis

Test the Hypothesis

Confirm or Refine the hypothesis/theory

The scientific method plays a vital role within Forensic science. Forensic scientist use the scientific method to develop a foundation of knowledge. It also forms the base for reconstruction and a logical and productive basis for investigations.

Physical Evidence:

• Physical evidence is introduced to a crime scene by changing the surroundings
  • depositing something at the scene
  • alteration of something that was there
• Any object can be physical evidence.
  • glass, hair, fiber, blood splatter, paint chips, etc.
  • Imprints or indentations
    • Footprints
  • Striations
  • Damage
• Transfer of materials from one object to another. Locard Exchange Principle

Initial Actions and scene security: first responders at scene

Proceed promptly and safely, Render aid and assistance, Effect preliminary notifications, Locate Witnesses, Investigate briefly and secure the scene, Maintain control, Interview witnesses, Note all conditions, Arrest the suspects as appropriate, Report fully and accurately, and Yield to continuing Investigations.

Investigation: Crime Scene Investigator

Scene survey and evidence recognition

Scene searches

Documentation: notes, sketches, photographs, and video

Evidence collection and preservation

Release of the scene

Reconstruction patterns that can be found at a crime scene:

• Blood Splatter Patterns: low-velocity, medium-velocity, and high-velocity. Contact deposit, wipe and swipe, arterial spurt, cast-off, running patterns, and secondary splatter.
• Glass fracture Patterns: tangential fracture lines and radial fracture lines​
• Tract and trail patterns: footwear, socks or stockings, bare feet, object or body being dragged.​
• Tire and skid mark patterns: tire imprints​
• Clothing and article or object pattern: overturned furniture, objects scattered, object in unusual areas or out of place, damaged items or clothing​
• Gunshot residue Patterns: deposited on hands of shooter, deposit next to item where gun was fired
• Projectile trajectory pattern: ballistics, wound ballistics. trajectory or flight of a bullet.
• Fire burn patterns: inverted cone or V-shape predicts fires starting point.
• Modus operandi patterns and profiling: language, methods of entry used, type of crime, use of weapons or no weapons, disguises used, and so on.
• Wound, injury, or damage pattern: wound and  injuries involve human body injuries. Damage involves damage seen on clothing