Fundamentals of Criminal Investigation
Investigation - an inquiry, judicial or otherwise for the discovery and collection of facts concerning the matters involved.
- it is the process of inquiring, eliciting, soliciting and getting vital information, facts, circumstances in order to establish the truth.
Criminal Investigator - a public safety officer who is tasked to conduct the investigation of all criminal cases as provided for and embodied under the revised penal code, criminals laws and special laws which are criminal in nature.
- a well trained, disciplined and experienced professional in the field of criminal investigation.
Custodial Investigation - investigation conducted by law enforcement officers after a person has been arrested or deprived of his freedom of action.
Neighborhood Investigation - one of the most crucial steps in kidnap for ransom cases which is often overlooked. The objective is to identify and interview in person all individuals in the area where the victim was kidnapped or last known sighting area during the window of opportunity.(last time seen until the time discovered missing.
Crime scene - a venue or place where the alleged crime/incident/event has been committed.
Corpus delicti - (latin for the body of the crime) - used to describe the physical or material evidence that a crime has been committed. ex. corpse of a murder victim.
Confession - is an express acknowledgement by the accused in a criminal prosecution of the truth of his guilt as to the offense charge.
Admission - refers to statement of facts not directly constituting an acknowledgement of guilt.
Organized criminal group - a structured group of three or more persons existing
for a period of time and acting in concert with the aim of committing one or more serious crime or offenses.
Organized crime - a combination of two or more persons who are engaged in a criminal or virtual criminal activity on a continuing basis for the purpose of profit or power using gangland style to attain their purpose.
Physical evidence - evidenced addressed to the senses of the court that are capable of being exhibited, examined or viewed by the court. This includes but not limited to fingerprints, body fluid, explosives, hazardous chemicals, soil/burned debris, bombs, electronic parts used in the commission of the crime.
Victimology/victim profiling - a detailed account of the victims lifestyle and personality, assist in determining the nature of the disappearance, the risk level of the victim and the type of person who could have committed the crime. Complete information regarding the victims physical description, normal behavior patterns, the family dynamics and known friends and acquintances should be obtained as soon as possible.
Miranda vs. Arizona - Ernesto Miranda had confessed to rape and kidnapping, after two hour interrogation. Because the interrogators failed to inform Miranda of his right to counsel and remain silent, his conviction was overturned.
Waterboarding - refers to the practice of strapping a suspect to a board with his or her head lowered, then the face is covered and water is poured over it causing the suspect to gag and experience the sensation of drowning.
Chinese water torture - interrogation technique, repeatedly dripping water on the forehead of the suspect. The goal is to drive the suspect to near insanity thereby obtaining a confession.
Serial Killer - is someone who murders 3 or more people with "cooling off" periods in between.
Police Blotter - is an 18" x 12" logbook with hard bound cover that contains the daily register of all crime incident reports, official summary of arrests and other significant events reported in a police station. A separate police blotter shall be maintained for offenses requiring confidentiality like violence against women and children and those cases involving a child in conflict with the law to protect their privacy pursuant to RA 9262 (anti violence against women and children act of 2004) and RA 9344 ( juvenile justice and welfare act of 2006).
Actus Reus - proof that a criminal act has occurred.
Sketch - a rough drawing or painting, often made to assist in making a more finished picture.
Types of Sketches
1. Floor plan (Birds Eye View)
2. Elevation Drawing
3. Exploded View
4. Respective Drawings
Allan Pinkerton - a Scottish american detective who created the Pinkerton National Detective Agency, the first detective agency in the US.Pinkerton foiled a plot to assassinate President Lincoln.
Rouges Gallery - is a police collection of pictures or photographs of criminals and suspects kept for identification purposes.A compilation of descriptions, methods of operation having places and names of criminal and their associates.
Mugshot - is a photographic portrait taken after one is arrested.
Criminal investigation - it is the collection of facts in order to accomplish the three fold aims:
3 Fold Aims Of Criminal Investigation
6 Cardinal points of investigation
Tools of an investigator in gathering facts
1. Information - data gathered by an investigator and other
person including the victim himself and from:
1. public records
2. private records
3. modus operandi file
2. Interview - skillful questioning of witness and
3. Instrumentation - scientific examination of real
evidence, application of instruments and
method of physical sciences in detecting crime.
Phases of investigations
1.Phase 1 - identify the suspect through:
2. eyewitness testimony
3. circumstantial evidence
4. associate evidence
2. Phase 2 - locate and apprehend suspect.
3. Phase 3 - gather and provide evidence to
establish the guilt of the accused.
Composition/Organization of an investigation team:
Equipment of an Investigator
Standard Methods of Recording Investigative Data:
2 Kinds of Information
1. Regular sources - ex. citizen, company records
2. Cultivated sources - ex. paid informant
1. Confession or Admission - is a declaration of an
accused acknowledging his guilt.
2. Eyewitness testimony
3. Circumstantial evidence
How circumstantial Evidence Obtained
3. Associative Evidence
Types of Interview
1. Informal (on the scene interview) - conducted by
police/investigator at the crime scene to get
description of criminal if seen.
2. Formal - interview conducted by the investigator
assigned to the case.
Types of Formal Interview
1. Normal - for willing or cooperative witness.
2. Group/Pretext Interview - for hostile witness or
witness who refuse to cooperate.
3. Follow Up - additional interview in addition to vital
points if necessary.
Qualifications of Interviewer
Requisites of an Interview
1. Establish rapport
2. Forcefulness of personality
3. Breadth of interest
Setting of Interview
1. Background Interview - time and place of
interview are not a consideration except for busy
2. Routine Criminal Cases - interview should be
carefully planned. Busy person can be interviewed
at night, privacy is important.
3. Important Criminal Cases - should be conducted in
places other than the subjects home/office to
prevent him/her feeling confident. Investigator
should get interviewees respect.
4. Appropriate Time - General rule - (ASAP) as soon
possible while facts are fresh in the memory of
Methods of Crime Scene Search
1. Strip method - the area is blocked out in the form
of a rectangle. The searchers (3 person is good)
proceed slowly at the same pace along paths
parallel to one side of the rectangle.
2. Double Strip Search Method - modification of the
strip search method. The rectangle is traversed
first parallel to the base then parallel to a side.
3. Spiral Search Method - The searchers (3 person is
good) follow each other along the path of a spiral
beginning on the outside and spiraling in towards
4. Zone Search Method - one searcher is assigned
to each subdivision of a quadrant and then each
quadrant is cut into another set of quadrants.
5. Wheel Search Method - the area is considered to
be approximately circular. The searchers gather at
the center and proceed outward along radii or
spokes. Procedure is repeated several times
depending on the size of the circle and the number