3I's of Criminal Investigation

• What are the three tools of criminal investigation referred to as the 3 I's?

  Information, Interview/Interrogation, Instrumentation
• What is the definition of information in the context of criminal investigation?

  • Knowledge or facts gathered by the investigator
  • Relevant to the commission of a crime or criminal activities
• What are the three classifications of information based on its sources?

  Regular Sources, Cultivated Sources, Grapevines Sources
• What are Regular Sources of information in criminal investigation?

  • Records and files from government or non-government agencies
  • News items, broadcasts, intercepted communications
• What are Cultivated Sources of information?

  • Information provided by informants or informers
• What are Grapevines Sources of information?

  • Information disclosed by underworld characters such as criminals, prisoners, or ex-convicts
• How does an informer differ from an informant?

  An informer is paid for information, while an informant provides information voluntarily.
• What are the two forms of information in criminal investigation?

  1. Sensory form: Acquired through the five senses
  2. Physical form: Information derived from physical objects or clues
• What is the purpose of an interview in criminal investigation?

  To obtain specific information from the person being interviewed.
• What does the I.R.O.N.I.C. format stand for in interviews?

  • Identity
  • Rapport
  • Opening Statement
  • Narration
  • Inquiry
  • Conclusions
• What is the Golden Rule in conducting an interview?

  Never conduct an interview if the interviewer has not gone to the crime scene.
• What are the qualities of a good interviewer?

  1. Rapport
  2. Forceful Personality
  3. Knowledge of Human Behavior
  4. Conversational Tone of Voice
  5. Acting Qualities
  6. Humility
• What are some reasons why witnesses refuse to talk or testify?

  • Fear of reprisal
  • Great inconvenience
  • Hatred against the police
  • Bias of the witness
  • Avoidance of publicity
  • Family restriction
• What are the stages of handling an interview?

  1. Preparation
  2. Approach
  3. Warming Up
  4. Cognitive Interview
• What are the rules in questioning a person involved in a crime?

  1. Ask one question at a time
  2. Avoid implied answers
  3. Questions should be clearly stated
  4. Saving faces
  5. Yes and no answers are not allowed
• What are the types of witnesses according to their attitude?

  1. Know-nothing Type
  2. Disinterested Type
  3. The Drunken Type
  4. Talkative Type
  5. Honest Witnesses
  6. Deceitful Witness
  7. Timid Witnesses
  8. Witnesses who refuse to answer
• What is the definition of interrogation in criminal investigation?

  It is the vigorous and confrontational questioning of a reluctant suspect about their participation in a crime.
• What are the legal requirements of interrogation?

  • The statement must be obtained voluntarily
  • No use of threat, fear, coercion, or duress
• What are some techniques of interrogation?

  1. Emotional Appeal
  2. Sympathetic Approach
  3. Friendliness
  4. Tricks and Bluff Techniques
  5. Stern Approach
  6. The Mutt and Jeff Method
  7. Removing the Ethnic or Cultural Barrier
  8. Searching for the Soft Spot
  9. Bluff on a Split Pair
• What are some additional modern techniques of interrogation?

  1. Rationalization
  2. Projection
  3. Minimization
• What are the physical signs of deception that investigators should observe?

  • Excessive sweating
  • Avoiding eye contact
  • Nervous gestures
• What is a common physical sign of deception that investigators should look for?

  Excessive sweating
• What is the importance of the investigator's approach in an interview?

  The approach sets the tone for the interaction and can influence the subject's willingness to cooperate.
• Who are the individuals mentioned that could act in a supportive role during an interrogation?

  The wife, the mother, the brother, the grandparents, or the best friend
• What does "Bluff on a split Pair" refer to in interrogation techniques?

  It refers to informing one suspect that another has talked to create pressure.
• What are the additional modern techniques of interrogation?

  • Rationalization: Using acceptable reasons for committing a crime.
  • Projection: Blaming others for the crime.
  • Minimization: Reducing the perceived culpability of the suspect.
• What is a physical sign of deception indicated by excessive sweating?

  It indicates tension, anxiety, shock, or fear.
• What does a change in face color during interrogation signify?

  It may indicate anger.
• What does dry mouth signify during an interrogation?

  It is a sign of great tension and a reliable symptom of deception.
• What does excessive breathing during questioning indicate?

  It indicates an effort to control breathing, often associated with deception.
• What does an increase in pulse beat indicate during an interrogation?

  It is indicative of deception.
• What does avoidance of direct eye contact suggest during an interrogation?

  It may indicate guilt or deception.
• What is the philosophy of interview and interrogation summarized as?

  • The RIGHT officer
  • Asking the RIGHT questions
  • In the RIGHT manner
  • At the RIGHT time and place
  • Will get the RIGHT answers
• What is instrumentation in criminal investigation?

  • Scientific examination of real evidence
  • Application of physical sciences in detecting crime
  • Known as "Criminalistics"
• What is the purpose of a polygraph test?

  It is used for lie detection.
• What is DNA fingerprinting considered in criminal investigations?

  It is the ultimate identification test.
• What is a unique characteristic of DNA profiles?

  No two persons have the same DNA profile, except identical twins.
• What are the three general groups of criminal identification methodologies?

  1. Criminalistics methods - scientific methods
  2. Methods using Eyewitnesses and Victims
  3. Methods using known criminals
• What are some examples of criminalistics or scientific methods?

  • Fingerprinting (Dactyloscopy)
  • DNA Analysis (Genetic Fingerprinting)
  • Blood Typing
  • Voice-print Analysis
  • Gait Analysis
  • Graphology
  • Cryptography
  • Odontology
  • Autopsy
• What does hair examination reveal in forensic science?

  It can determine the presence of drugs taken up to two years prior.