fingerprint · 2020. 5. 2. · national police cadet corps activity time developing latent...
TRANSCRIPT
Fingerprint
National Police Cadet Corps
Crime Scene Investigation Unit• Well done on completing the first step of becoming an Assistant Investigation
Officer (AIO). Now that you have gone through the Crime Scene
Investigation Introduction, you will proceed to learn more about the
importance of establishing & developing fingerprints found in a crime scene.
• With the knowledge, you will then be tasked to assist the Chief Investigation
Officer (CIO) in several cases which involves some fingerprint dusting
activities.
National Police Cadet Corps
National Police Cadet Corps
Learning Objective Learning Outcome
Create awareness on the importance
of establishing & developing
fingerprints found in a crime scene
To manage self-expectations (in a task
that requires patience and
meticulousness) and actively
contribute to a team goal using
collaboration skills.
Purpose of Search for Fingerprints
• Fingerprints found in a crime scene can help to identify possible suspects of
a crime
• Crucial for police officers to preserve fingerprints to aid in solving a crime
• Fingerprints can also be used to convict a suspect in the court of law
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Types of Fingerprints
National Police Cadet Corps
National Police Cadet Corps
IMPRESSION
Print deposited in a material that retains
the shape of the ridge detail
VISIBLE
Print that can be plainly seen
(made visible by contaminants e.g. oil, grease, blood,
etc)
LATENT
Print that cannot be seen with the
naked eye
Types of Fingerprints
• Impression Fingerprints
• Impression is made on soft surfaces like cheese or plastic explosives
• Visible Fingerprints
• Prints left on objects after skin coming into contact with stains
• Rare to find unless the crime was particularly violent or gory
• Latent Fingerprints
• Fingers have friction ridges used to grip surfaces
• Friction ridges are covered with sweat and oils secreted by the skin
• These sweat & oils will be transferred to surfaces they come in contact with, as an invisible
pattern of fingerprint
National Police Cadet Corps
Types of Fingerprints
Where can Fingerprints be Found?
• Fingerprints of an individual can be found on any objects, that the individual
has been in contact with
• Any objects found in a crime scene can be a potential source of evidence
• Tampered fingerprints cannot be used by police officers as evidence thus it
is important not to tamper with the objects found in a crime scene
National Police Cadet Corps
National Police Cadet Corps
SURFACES- window
PROPERTIESRECOVERED
TOOLS LEFT BEHIND
GLOVES
CIGARETTEBUTTS
SURFACES- door
SURFACES- vehicle
Where can Fingerprints be Found?
National Police Cadet Corps
Where can Fingerprints be Found?
NON-POROUS SURFACES
• Not permeable to water, air, or other fluids
• Print found on such surface is very fragile
• Glass, metal, plastics
POROUS SURFACES
• Permeable to water, air, or other fluids
• Print are absorbed into the material
• Paper, cardboard, raw wood
QUIZ TIME!
National Police Cadet Corps
Name the 3 types of fingerprints that can be found.
• Impression
• Visible
• Latent
National Police Cadet Corps
Quiz Time
Fingerprint dusting powder can only be used on which type of fingerprints?
• Latent prints
National Police Cadet Corps
Quiz Time
Which type of surface (porous or non-porous) would you find fingerprints that
are fragile?
• Non-Porous surface
National Police Cadet Corps
Quiz Time
A fingerprint of Ali was found in a crime scene. The police officer ,Bala, found a
match in the fingerprint database with Ali’s fingerprint. He concluded that Ali
was the culprit. Is Bala right?
• No, solely fingerprints cannot be used to incriminate a person. It can only be
used for substantiation. More evidences must be collected & collated to form
the whole picture of the crime before a conclusion can be made.
National Police Cadet Corps
Quiz Time
National Police Cadet Corps
Quiz Time
What is the Learning Objective?
• Create awareness on the importance of establishing & developing
fingerprints found in a crime scene
National Police Cadet Corps
Quiz Time
What is the Learning Outcome?
• To manage self-expectations(in a task that requires patience &
meticulousness) & actively contribute to a team goal using collaboration
skills
National Police Cadet Corps
Activity Time
• Now you are ready to assist the Chief Investigation Officer (CIO) in a high
profile case we have on hand. The real action will now begin. Be careful, be
accurate, good luck.
National Police Cadet Corps
Activity Time
Developing Latent FingerprintsLogistics
•Fiber Brush
•Black Powder
•A sheet of clean white paper
•Scissors
•Gloves
Procedure
•Pour some black powder on the sheet of clean white paper
•Lightly dab brush on black powder1.Only need tips of the brush to be coated
•Stroke the brush on the object for developing fingerprints1.Twirl the brush on the surface of the object for better development of fingerprints
2.Not much contact is needed. Just lightly twirl on the surface of the object
3.Twirl on the surface of the object a few times; going in small circles
4.Applying too much pressure on the surface of the object may smudge the print
•Stroke the brush on the object until fingerprints are seen
•Lightly stroke away any excess powder
•Pour the remaining black powder, on the white paper, back into the jar1.Ensure that the powder to be stored has not been contaminated
Q & A
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Congratulations!
• Congratulations! Your important work has contributed to solving the case.
Our colleagues are on their way to arrest the suspects now, and your work
will serve as evidence in court. Good job!
• CIO has recommended you for promotion to Investigation Officer and
Manpower Department will inform you of the decision before the year ends.
There will be another series of tests and interviews before you can be
admitted to the Intermediate CSI training module, where you will learn Police
Photography, DNA Analysis and Bloodstain Pattern Analysis. Till then, all the best!
National Police Cadet Corps
THANK YOU
National Police Cadet Corps