UNIT III

TOOLS OF CRIMINAL INVESTIGATION

Four I’s of Criminal Investigation

There are indispensable tools that can be used by criminal investigators to successfully
solve criminal cases. These are the following:
1. Information
2. Interview
3. Interrogation
4. Instrumentation
Depending on the necessity to establish the guilt of the accused during trial, the uses of
these tolls vary based on actual situation.

Information
It is composed of sets of data or raw facts that were collected and then put together to
form a significant idea of something.
It is the general term referring to the knowledge acquired by criminal investigators form
various sources, which could be in the form of person, places, (crime scene) or things
(record/files or physical evidence).

Significance of Information in Criminal Investigation

a. Information provided answers for the 5Ws and 1H.
b. Information is vital in planning the operations of investigators.

Objectives of Information
a. Develops leads.
b. Establishes prima facie evidence.
c. Establishes corpus delicti.
d. Establishes identification of persons.

Techniques of Gathering Information

Skillful gathering and systematic development of information can be done in the
following manner:
a. By observing tact or diplomacy in performing investigative techniques and duties. “Tact”
involves the skill or knowing how to use diplomatic words, thus avoiding offensive
language for the purpose of winning goodwill and confidence of other people.
b. Being friendly and diplomatic with other peace officer or law enforcers.
c. By not totally relying on memory - Making the habit of jotting down notes of every
circumstance or incident in countered during the investigation proceedings.
d. By keeping records or maintaining a file of potential, criminals, suspected criminals,
actual offenders and informants/informer.
e. By being meticulous - learning not to overlook or disregard chance memoranda or
haphazard notices.
f. By being acquainted with many kinds of people from all walks of life.

Traces of Information
a. Any written or documented statement of persons who possesses relevant knowledge
concerning a crime.
 b. It covers any object of recorded data that can be used by investigators in their inquiry
concerning a criminal incident.

General Types of Information

a. Open Sources
b. Closed Sources

Three General Categories of Sources of Information

1. Place
The crime scene is usually the focus of criminal investigation in its initial stage since it
contains most, if not all of the vital information needed to solve criminal case. At the crime
scene, evidence composing the corpus delicti can be recovered.
2. Things
The source of information is usually in the form of record or files or and banks record.
Police station has files on fingerprint, modus operandi, blood and deoxyribonucleic acid (DNA)
types, including photographic files (mug file). These records and files are extensively used as
means of identifying and tracing criminals.
3. Official records that serve as vital sources of information including the
following:
a. Criminal records - police files and NBI files
b. Court records
c. Bureau of internal revenue (BIR) records
d. Prison files
e. Hospital records
f. Land transportation office (LTO) records
g. Bank records
h. School records
i. Telecommunication files
4. Persons
Human sources will be the offended party (the victims or his kin), witnesses (bystanders
or friends of victims), suspects , criminal , informants and informers.
Information is usually obtaining by interviewing the offended party or eyewitness of the
crime.

Classical System of Gathering Information

There are two classical practices of gathering information that is basically the roots of
what the investigators are using today.
a. French System – this involves the practice of or obtaining information that relies
heavily in buying information. Hence, it advocates the extensive use of informers.
b. English System – this is the practice of gathering information that has little
regard/consideration on paid information. It is the system that relies more on the
information provided voluntarily or willingly by patriots or civic minded informants.

Informants and Informers

1. Informant
One who voluntarily or willingly provides information to the criminal investigators and
even offers to be a witness. There are times, however, even when the informant gives
information secretly or surreptitiously, and requests anonymity.
 2. Informer
a. Informer is informant by profession, usually a recruited or paid asset of the
investigator.
b. Informer is distinct from informant as the former gathers information of criminal
interest while the latter provides information on non-criminal nature.
c. The informer uses information as means of livelihood since it is his job to collect
criminal facts (and sometimes rumors) then reveals/discloses them to Law
Enforcement authorities in consideration (exchange) of something. If he provides
information, he will always expect something in return.

General Types of Informants

1. Anonymous Informants includes those anonymous telephone callers or letter writers
who give information about suspects or fugitives of justice.
2. Rivel Elimination Informant is usually as his purpose in providing information is to
remove rival person or gang due to competition or other motives such as revenge, etc.
3. False Informant reveals information usually of no consequence, value or stuff
concocted with thin air. His purpose is to appear to be on the side of the law and for the
purpose of throwing the suspicion form himself or form his gang or associates.
4. Frightened Informant is prodded by fear or self-interest in giving information to the
police. He maybe one of the lesser gang members who runs to the police when his hang
mates are about to be involved in dangerous situations or when the gang he belongs is
hot on the police trail. Motivated by anxiety and self-preservation of his well-being. The
weakest link in the composition of the criminal chain.
5. Self-Aggrandizing Informant moves around the centers of criminals, group or
syndicate and delights in surprising the police about bits of information. His information
may be of value by way of authentication in intelligence operation.
6. Mercenary Informant has information for sale. He may have been victimized in a
double-cross or little share in the loot or given a dirty deal and seeks revenge as well as
profit in his disclosure.
7. Double-Crosser Informant uses his seeming desire to divulge information as an
excuse to talk to the police in order to get more information from them more than he
gives. To counter this kind of informant, the police apply the deception method by giving
him false information that will lead to his capture.
8. Woman Informant is usually a female associate of criminals. She gives info because
her criminal lover has jilted her. Her motives are either revenge or jealousy. She maybe
able to give info but the investigator must be careful because the female specie is more
deadly than the male.
9. Legitimate Informant includes operators of licensed premises who do not want their
place of business to become the hangout of dangerous criminals.
10. Incident Informant or Automatic Informant personally saw the crime.
11. Confidential Informant is a person who provides the police with confidential
information concerning a past or a projected and planned crime. He does not want to be
identified as the source of the information. Under the law, these informants are
protected and their identity could not be revealed by the police even under the order of
the Court unless on exceptional case where there is a claim by the defense that the
informant framed the accused.

Types of Informers
 1. Recruited Informer
2. Dual or Multiple Informer
3. Paid Asset
4. Double Crosser
5. Intelligence Broker

Common Motives of Informants and Informers

1. Vanity - The motive is for self-aggrandizement by gaining favorable attention and
importance from the Police.
2. Patriotism or Civic Mindedness - This is the motive of civic-minded person with good
reputation in the community who are interested in seeing that justice is done.
3. Repentance - Those lesser criminals such as accomplices or accessories who will have a
change in heart to unburden their conscience
4. Fear - It is engendered illusion of oppression from enemies or from impending danger
5. Avoidance of Punishment
6. Showing gratitude for gaining something
7. Competition
8. Revenge
9. Jealousy
10. Remuneration

Methods of Obtaining Information

Information can be obtained or developed by conducting overt or covert operations.

Over Operation of Gathering info include the following:

1. Interview
2. Patrol and reconnaissance
3. Crime scene search
4. Regular performance of policing activities
5. Custodial interrogation

Information can also be acquired through cover operation. Clandestine operations employed by
obtain info including the following:
a. Surveillance – physical or technical; fixed or mobile; visual or audio
b. Undercover assignment – roping, penetration, infiltration
c. Entrapment – buy-bust operation
d. Tactical Interrogation

Surveillance is one of the most important clandestine methods of gathering

information. Surveillance serves several purposes such as;
a. Obtaining evidence
b. Supplying info as basis of issuing arrest or search warrant
c. Determining the activities and contacts of suspected criminals
d. Catching criminals in Flagrante Delicto

Interview
It is the simple and friendly questioning of people who have the information officially
needed by investigators.
 In interview, the person being questioned is usually ready, willing and able to talk freely
thus, providing his testimony on how the criminal incident took place, offering information in his
own manner and wordings.

Types of Interview used in Criminal Cases

1. Background Interview
This is the kind of Interview that is focused only in obtaining data regarding the
personal background of the subject, the simplest type of Interview used in criminal case.
The Background Data that must be indicated;
a. Date and time of interview
b. Setting/place of interview
c. Full name of the subject
d. Address of the subject-past and present place of residence
e. Educational Background
f. Names and where about of relatives
g. Personality traits, habits and hobbies
h. Marital Status and numbers of children
i. Profession or vocation
j. Type and tenure of employment or contract
k. Name or employer, superiors, and / or associates in his job.
l. Membership in any organization
m. Honesty, discretion and loyalty to his job and his organization.
n. References for evaluation of the subject
2. Subjective Interview
This is the type of interview wherein the questions are phrased in a manner such that
the subject's answers are based on his personal opinions or views.
Questions are designed to deal with the subjective aspect of the case.
3. Objective Interview
In this type of interview, questions are designed to acquire the basic and specific or
facts regarding a criminal case.
This is the type that complies with the 6 cardinal points of criminal investigation - the
5Ws and 1H.

Steps in Conducting Interview

a. Preparation
b. Approach
c. Warming-up
d. Recounting
e. Questioning for Clarrification
f. Ending the Interview

The Interview Format (IRONIC)

1. Identity
2. Rapport
3. Opening Statement
4. Narration
5. Inquiry
 6. Conclusion

Rules to be Observed in Questioning

1. One question at a time
2. Avoid implied answer
3. Simplicity of questions
4. Saving faces
5. Should not be answerable by yes or no
6. Positive attitude

Types of Witnesses according to their attitudes

1. Know-nothing type
2. Disinterested type
3. Drunken type
4. Suspicious type
5. Talktative
6. Honest
7. Deceitful
8. Timid
9. Boasting, egoistic, or egocentric
10. Refusal talk

Interrogation
It is the vigorous or aggressive questioning of a person suspected of having committed
an offense or of person who is reluctant or unwilling to make a full disclosure of information in
his possession, which is pertinent to the investigation of a criminal case.
It is the vigorous and confrontational questioning of a suspect about his participation in
a crime. It is confrontational in the sense that the investigator places the guilt on the accused.
This process is also applied to an uncooperative witness/es.
It is an art employed in the questioning of suspects for the purpose of eliciting or
obtaining facts that usually result to his admission and / or confession about the commission of
a felony or offense.
It is a formal questioning whereby aggressive and accusatory questions can be asked
the subject. It refers to the questioning of suspects, culprits, offenders, or perpetrators of a
crime. In practice, it is sometimes used in questioning hostile witnesses.

Purposes of conducting interrogation

a. On the part of the suspect, it is to extract a confession or admission.
b. On the part of the uncooperative information he possesses.

Requirements of the interrogation room

a. Private
b. Simple
c. Devoid from Ornaments
d. Technical Aids

Characteristics of an Effective Interviewer/Interrogator

 Many of the emotional and intellectual traits of an investigator are especially valuable in
communicating with others. Presenting a favorable appearance and personality and establishing
rapport are more important than physical attributes. Sometimes, however, it is an advantage to
be of the same race or gender as the person being questioned. Under some circumstances, it is
better not wear a uniform. Sometimes a suit or jeans are more appropriate.
1. Adaptable and culturally adroit - Your cultural and educational background and
experience affect your ability to understand people from all walks of life, to meet them
on their own level on varied subjects and to adapt to their personalities, backgrounds
and lifestyles.
2. Self-controlled and patient- Use self-control and patience to motivate people to talk.
Be understanding yet detached, waiting for responses while patiently leading the
conversation and probing for facts Remain professional, recognizing that some people
you interview may feel hostile toward you.
3. Confident and optimistic - Do not assume that because the person you are
questioning is a hardened criminal, has an attorney, is belligerent or is better educated
than you that no opportunity exists to obtain information. Show that you are in
command, that you already know many answers and that you want to corroborate what
you know. If the conversation shifts away from the subject, steer the discussion back to
the topic.
4. Objective - Maintain your perspective on what is sought, avoiding preconceived ideas
about the case. Be aware of any personal prejudices that can interfere with your
questioning.
5. Sensitive to individual rights - Maintain a balance between the rights of others and
those of society. Naturally, suspects do not want to give information that conflicts with
their self-interests or threatens their freedom. Moreover, many citizens want to stay out
of other people business Use reason and patience to overcome this resistance to
becoming involved.
6. Knowledge of the elements of the crime - Know what information you need to prove the
elements of the crime you are investigating. Phrase questions to elicit information
related to these elements.

Interrogation Techniques
1. The "Open technique" - Here, the interrogator is open and in approach and makes no
attempt to conceal the purpose of the interrogation. This is best employed when the
subject is cooperative.
2. The "Common Interest" - The interrogator must exert effort to impress the
interrogee of their common interest. The officer must look or point out the real
advantages the interrogee may get if he/she cooperates
3. Record File (we know all technique) - The interrogator prepares a file about the
subject/source listing all known information (record should be padded to make it appear
to be very extensive). The information must contain the life history of the subject like
his activities and known associates (Bio data or resume of the subject is important). The
"we know all" is used in conjunction with the record file. During the approach, the
interrogator may ask the interrogee about a subject If he refuses to cooperate, the
interrogator may provide the answer in order to impress him that the interrogator knows
him very well (all is supposedly known).
4. Opposite personality techniques - also known as "Mutt and Jeff: "Threat and
rescue": "Bad Guy-Good Guy": "Sweet and Sour Sugar-Vinegar: "Devil-Angel.
 5. Silent Technique - This is employed against nervous or the confident type interrogee.
How it is done?
a. Look at the interrogee squarely in the eye with sarcastic smile (force
him to break eye contact first)
b. The interrogee/subject may ask question but the interrogator must
not answer.
c. Patience is needed.
d. When the interrogator is ready to break silence, he may do so with a
quiet and non-chalant question that the interrogee is sure of being a
part of the subject.
6. Question Barrage Technique (Rapid Fire Questioning)- This is intended to
confuse the interrogee and put him into a defensive position. The interrogee becomes
frustrated and confused. Then, he will likely reveal more than he intended Thus,
creating opening for further questioning.
7. Emotional Appeal - This is a technique where the investigator, combining his skills of
an actor and a psychologist, addresses the suspect with an emotional appeal to:
confess. This is applicable to first time offenders or those who are of the emotional type
of characteristics displayed by nervousness or emotional disturbances. Devotees of a
religion may belong to this type.
8. Sympathetic Approach - The investigator, in his preliminary or probing questions
must dig deep into the past troubles, plight and unfortunate events in the life of the
suspect. An offer of help, kindness, friendliness, may win his cooperation.

Tricks and Bluffs

a. The pretense of solid evidence
b. The weakest link
c. Drama
d. Reigning contact with Family Members
e. The Line up
f. Reverse Line up

Stern Method
a. Pretense of a physical evidence
b. Jolting
c. Indifference
d. Affording an opportunity to lie

Rationalization - It is the use of reasons, which is acceptable to the subject that led to the
commission of the crime. Thus, it may be said that sometimes, killing is a necessity rather than
by purpose or design. Robbery maybe a necessity to feed a starving family. The application of
this technique depends upon the nature of the crime.

Projection - It is the process of putting the blame to other persons, not alone to the suspect.
The murderer may blame the mastermind for corrupting him with big sums of money, or the
mastermind blaming the greediness of the victim or the husband blaming the wife for her
infidelity. Or that it is a necessary evil as the victim is planning to kill the suspect.
Minimization - It is the act of minimizing the culpability of the suspect. The investigator
convinces the suspect that a confession will reduce the offense and the penalty. Thus, it could
be studied by the investigator if there is a way to downgrade murder to homicide or the
introduction of mitigating circumstances with the result of the penalty being within the range of
probation.

Approach and Probe

Approach - the process of setting people to start talking
Probe - the process to keep the person (subject) talking uncessantly.

The Interrogation Session

1. Interrogation session offers the suspects opportunity to clear him or to spill
and hope for the best.
2. Investigator conducting an interrogation must be:
a. Prepared
b. Up to date on the reconstruction of the crime
c. Cognizant of the facts secured in parallel inquiries into motive and opportunity
d. Know as much as possible about the suspects and the facts connecting him or
her with the crime
e. Know the finding of the criminalist who examined any physical evidence that has
been collected
f. Certain that the suspect is not in an emotional state that might impair his or her
capacity for rational judgement.
g. The Interrogation is similar in structure to interview proceeding in the sense that
it has a beginning, a main body and a conclusion.

Stages of the Interrogation Session

1. Initial Stage - (Introductory Part)
Introduction of material necessary to establish the integrity of the interrogation.
Clearly state the reason for the suspects’ presence, and establish the crime about which
he or she is to be questioned the name of the victim and the time and place of crime.
Level with the suspect by indicating or explaining that the interrogation is not an
attempt to deceive but an inquiry being conducted because evidence has indicated his
knowledge of or participation in, the crime under investigation.
2. Focusing Stage – (Main Body)
Questions are concerned with the activity and where about of the suspect during the
time of the crime.
Questions are concerned wither the suspect had even been at the scene or in contact
with the victim and under what circumstances.
3. Concluding Phase – (Closing Part)
In case of confession, take a formal statement of the suspect.
Ask the classic concluding question such as "Is there anything else you wish to talk
about or any correction you wish to make in your story at this time?"

Three Main Questioning Techniques

To elicit facts from suspects, the following techniques may be used:
1. Chronological Questioning
a. The easiest technique.
 b. The Interrogator is almost sure of getting all the necessary information. a Start
at very beginning of the crime by asking the ff:
i. The planning;
ii. The commission, and
iii. What happened after the crime was committed.
2. Going Backwards – Flash Back Technique
Start questioning on the last known act, then backwards to the idea of committing the
crime.
Ask questions that elicit an acknowledgement of guilt and work back (backtrack)
towards the planning stage of the Crime.
This is advantageous when suspect acknowledged his guilt at the early stage. Once a
suspect has committed himself, he is Fairless likely to talk at continuing with the
details.
This technique is somewhat harder than the first since most people tend to think in
terms of what happened first, then second, and then the last.

Methods of Reproducing an Interview/Interrogation

1. Mental notes
2. Written notes
3. Stenographic notes
4. Audio recording
5. Sound and motion recording

General types of Recording

1. Overt Transcript
2. Surreptitious Transcript

Instrumentation
This is defined as the application of instruments and methods of physical to detect and
investigate crimes, the sum total of the application of all sciences in crime detection and it is
not only confined in the crime laboratory.

Criminalistics
This refers to the profession and scientific discipline directed to identification,
individualization and evaluation of physical evidence by application of the natural sciences in
matters of law and Science.

Why does Instrumentation cover Criminalistics?

Instrumentation covers criminalistics because criminalistic is a broad field that
exclusively uses scientific knowledge in examining and evaluating the legal value of forensic
evidences. On the other hand, the setting of examination or analysis of evidences in
instrumentation is not only confined at the crime laboratory but most often than not outside the
crime laboratory.

Limitation of Criminalistics/Forensic Science

When there are no physical evidences recovered or found at the crime scene or from
any other place or persons that the crime laboratory technicians can work onto help the
investigators solve a case.
Criminalistics Provides Ways of Solving Criminal Cases by:
1. Supplying one or more missing links in a chain of evidences,
2. Strengthening a weak link or links in the chain of evidences;
3. Checking the accuracy of the statements made by suspects, and materials witnesses;
and
4. Providing knowledge to the Investigator that assist/guide him in rapid clearing.

Forensic Science as Applied to Criminal Investigation

The term forensic science and criminalistics are often used interchangeably. Forensic
Science is that part of science applied to answering legal questions. It is the examination,
evaluation, and explanation of physical evidence in law. It encompasses the following:
a. Pathology
b. Toxicology
c. Physical anthropology
d. Odontology
e. Psychiatry
f. Questioned Documents
g. Forensic Ballistics
h. Tool Marks Comparison
i. Serology, etc.
Specifically, criminalistics can be considered a branch of forensic science that deals with
the study of physical evidence related to a crime.

Identify the Criminal

What is the scope of Criminal Identification?
1. Suspect identification.
2. Identification of actual perpetrator.
3. Identification of dead body and other victims.

Two Kinds of Criminals identified by the witnesses:

1. Known Fugitive
2. Unknown Criminals

Two kinds of suspect identification:

1. Positive Identification uses information that identifies an individual beyond question and
is legally acceptable as pertaining to and originating from a particular individual (semen,
F.P., DNA results, blood analysis)
2. Tracing Identification involves the use of all other information that maybe indicative of
the personal identity of an individual such as: (description of witness, personal
belongings present at the crime scene.)

Identification of Criminal by Confession and Admission

1. Portrait Parle (Verbal Description) method becomes successful depending on the
ability of a witness to describe the person he saw committing the crime.
2. Rogues Gallery (use of photographic files) method is successful if there is an
existing photograph of the perpetrator in the files/gallery of the police law enforcement
agencies
 3. General Photograph method includes the investigator showing variety of facial types
that may not be necessarily/directly represent the face of the criminal.
4. Cartography (Artist's Assistance) is when the witness and investigator develop a
picture of the criminal with the help of a skilled cartographer actual drawing
5. Police Line-Up (Show ups) involves a process of letting/allowing a witness to select
the primary suspect from a group of chosen persons (suspects and innocent persons).

Criminal bad luck is an unconscious or sublime act aiming at self betrayal a.k.a
*VEBRECHERPECH" clue which may result to the identification of perpetrators:
1. Faulty acts
2. Carelessness
3. Negligence
4. Vanity - believe on ones cleverness or excessive pride

Modus Operandi (MO) File

1. Modus Operandi came from Latin term for mode or method of operation.
2. It is a summary of habits, techniques and peculiarities, methods, tools used in obtaining
the crime and physical condition at the crime scene.

Factors Influencing MO
1. Opportunity, desire, motive/intent
2. Knowledge
3. Experience
4. Conditions

Identification of Criminal by Circumstantial Evidence

1. Motive

Identification of Criminal by Associative and/or Tracing Evidence Identification of

Persons in General
1. Ordinary Method
2. Scientific Method