Crime Scene Investigation Basics

Crime Scene Investigation

• The purpose of crime scene investigation is to establish what happened at the crime scene and identify the responsible person(s).
• Thorough documentation and recognition of all important physical evidence is crucial.
• Proper evidence collection is vital for solving and prosecuting crimes.
• Actions taken at the crime scene can significantly impact a case's outcome.
• Criminal investigators are responsible for criminal investigation objectives like identifying and locating suspects and providing evidence of their guilt.
• Investigator/Officer refers to law enforcement personnel enforcing Republic Act 9208. This includes officers, investigators, agents from the Philippine National Police (PNP), National Bureau of Investigation (NBI), and Bureau of Immigration.

Primary Responsibilities

• Crime scene investigators (CSI) are multi-faceted professionals with various sub-specialties focused on collecting, preserving, and processing evidence at crime scenes.
• CSI professionals are trained to collect, preserve, and process evidence, unlike forensic scientists who perform tests in a lab.
• CSI ensure evidence is documented according to strict codes and transported to forensic labs.
• Primary responsibilities of a criminal investigator include, but are not limited to:
  • Processing crime scenes by recognizing the scene, documenting it, and collecting evidence.
  • Adhering to applicable laws governing investigations.
  • Initializing surveys and generating theories.
  • Thoroughly documenting scenes and collecting evidence (physical, specimens, documents, photographs, statements).
  • Drafting detailed investigative reports for the prosecutor.
  • Preserving, collecting, and recording impressions (tool marks, footprints, tire marks, bite marks, fingerprints).
  • Collecting DNA evidence (blood, semen, hair, skin, bloodstains, bodily fluids, nails).
  • Collecting trace evidence (gunshot residue, fibers, accelerants, paint, glass).
  • Collecting firearms evidence (weapons, casings, bullet fragments, cartridges, guns, gun powder patterns)

Additional Responsibilities

• Investigating criminal acts (murders, homicides, sexual assaults, robberies, home invasions, and property crimes).
• Interviewing informants, suspects, and witnesses to understand alibis, clues, timeframes.
• Collecting sufficient evidence for a court case.
• Preparing sketches and diagrams.
• Obtaining search warrants.
• Performing surveillance and monitoring suspects.
• Exchanging information and coordinating with other departments.
• Recording physical information about suspects.

Crime Scene Investigation Procedures

• Following all laws.
• Thoroughly documenting the crime scene and all collected evidence.
• Processing evidence quickly and correctly.
• Avoiding any actions that may compromise evidence.
• Using proper evidence recovery methods.
• Proper handling, packaging, and transportation of all collected evidence.

Investigator Qualities

• Proven experience in criminal investigation
• Hands-on experience with crime scenes and forensic science
• Proficiency in interpreting evidence and reconstructing events
• Detailed report generation skills
• Deep understanding of criminal law, rules, and legislation
• Familiarity with different types of evidence
• Strong analytical skills
• Good interviewing and interrogation skills
• Honesty, ethics, and confidentiality

Investigation Goals

• Identify the suspect
• Locate the suspect
• Develop evidence of guilt

Cardinal Points of Investigation

• Determining the specific offense committed.
• Identifying the date and time of the crime.
• Determining the location of the crime.
• Identifying the perpetrator.
• Determining the motive.
• Determining the method of the crime.

Custodial Investigations

• Investigations conducted by law enforcement officers after a person is arrested or deprived of freedom, including invitations to persons suspected in crimes.

Miranda Doctrine

• A suspect's right to remain silent during police interrogation, derived from Miranda v. Arizona. Suspects have the right to an attorney and if they can't afford one, one will be provided.

Combined Task Forces

• Multi-disciplinary and jurisdictional teams for investigations involving serious crimes (drugs, terrorism, gangs).

Case Officer

• The individual responsible for a case's investigation.

Case Operational Plans

• Detailed plans developed to carry out case operations for complex investigations failing normal police methods.

Probable Cause

• Sufficient evidence to convince a reasonable person a suspect committed a crime.

This quiz explores the fundamental concepts of crime scene investigation, focusing on the roles and responsibilities of criminal investigators. Learn about the importance of evidence collection and the impact of crime scene actions on case outcomes. Ideal for students and professionals interested in forensic science and law enforcement.