Transcript Lesson 1 Crime Scene Investigation

Lesson 1
Crime Scene
Investigation
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Case Reading 1
A woman was killed in a “robbery”.
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A man called 999 that his wife was
killed by a robber and he suffered from
2 gunshot wounds (one at his left arm
and the other at his left thigh) at 11
o’clock at night while they were walking
along the beach.
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Activity 1.1 General Crime
Scene Procedure
Suppose you were the senior police officer
who would take charge of the crime scene
investigation upon receiving the 999 call.
What would be the general crime scene
procedure?
Instruction:
 Divide yourselves into groups of 4
students. You would have 15 min. for
group discussion.
 Group presentation: 10 min.
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Activity 1.1 General Crime
Scene Procedure
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To assist/help/protect the victim if he/she is still
alive by carrying out first aid and/or calling the
ambulance;
To assess the crime scene;
To seal the crime scene – it helps preserve
important forensic evidence and identify
potential suspect(s)/witnesses by eliminating
the possibility of people leaving or entering the
crime scene before the completion of the crime
scene investigation;
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Activity 1.1 General Crime
Scene Procedure
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To detain the potential witnesses and
suspects and remove them from the crime
scene to be questioned separately or
even searched by police officers if
necessary;
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Activity 1.1 General Crime
Scene Procedure
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To identify the crime and categorize the
crime into burglary, robbery, arson, murder,
kidnap, sexual assault, etc.;
To document the crime scene-the forensic
photographers help record the crime
scene by means of cameras, digital
cameras and video cameras;
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Activity 1.1 General Crime
Scene Procedure
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To search for evidence;
To do forensic analysis in the
laboratory;and
To reconstruct the crime scene (at a later
stage).
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Activity 1.1 General Crime
Scene Procedure
Questions
(a) Why do police officers usually question
potential suspects/witnesses separately?
(b) It is suggested that it is not good to
collect too much or too little evidence.
Please comment.
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Activity 1.1 General Crime
Scene Procedure
Suggested Answers
(a) To prevent the witnesses discussing
what they each saw and prevent one’s
recall of the incident being influenced by
the ideas of others
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Activity 1.1 General Crime
Scene Procedure
Suggested Answers
(b) It is not cost effective to collect irrelevant
evidence. However, if we collect too little
evidence, some important forensic evidence
may be missing which in turn would affect the
crime investigation. Experience in collecting
forensic evidence may help solve this problem.
However, one should always note that minor
evidence may contribute much to solve the
crime case.
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Activity 1.2 Crime Scene
Search
After crime scene documentation (taking
notes, videos and photos) is completed,
the crime scene is searched for more
physical evidence
There are some searching patterns
commonly used by the police:
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Activity 1.2 Crime Scene
Search
(a) Chose a search pattern for your group
and look for some missing objects (not
related to the said crime) within 5 min.
(b) What are the pros and cons of your
searching pattern in looking for forensic
evidence?
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Remarks:
If necessary, the practical application of
the search methods to a crime scene
may be a combination of different
methods.
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Activity 1.3 (Secure a Crime Scene)
Referring to the Crime Scene Photos and
the Crime Scene Sketch in worksheet 1.3
(a) establish a perimeter to secure the crime
scene. The perimeter is delineated by
“police barricade tape” with words
“POLICE CORDON DO NOT CROSS”
(警察封鎖線 不得越過)
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Activity 1.3 (Secure a Crime Scene)
(b) Place numbered evidence markers to
show the location of the pistol (a pistol
was found 50 m from the dead body near
the rocks), dead body, etc. at the crime
scene.
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Not
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Activity 1.3 (Secure a Crime Scene)
Suppose you were required to search the
above crime scene for any physical
evidence.
(a) How would you do the searching?
Explain why you choose such search
option.
(b) What important information is missing in
the given crime scene sketch?
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Not to scale
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Not to scale
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Not to scale
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Activity 1.3 (Secure a Crime Scene)
Answer to (a)
 It depends on the environment, crime
cases and manpower, etc.
Answer to (b)
 Missing elements are the time, description
of the crime and the measurements of the
crime scene.
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Activity 1.4 Collection of Forensic
Evidence
(a) What information and /or forensic
evidence you would like to obtain/collect
for testing in the forensic laboratory
regarding this crime case?
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Evidence Collection Kit
http://store.sirchie.com/SEARCH-3-DrawerStorage-Evidence-Collection-Kit-P1676C468.aspx
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Suggested answer:
(a)
 Oral confession of the husband, local
residents at region I and passersby
along the Silverstrand Beach Road;
 Autopsy report; and
 Forensic evidence collected (e.g.
fingerprint, footprint, blood spatter
pattern and DNA evidence).
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Activity 1.4 Collection of
Forensic Evidence
(b) Tell your teacher what sorts of
information and/or forensic testing result
you need. Then get the relevant
information sheets from your teacher if
he/she has got them.
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Activity 1.5 Crime Scene
Reconstruction
(a) Based on the information you gathered
and the forensic evidence try to
(i) evaluate the forensic evidence and
the credibility of the oral confession of
the and
(ii) RECONSTRUCT the above crime
scene.
(b) Presentation
(c) What are the limitations to reconstruct a
crime scene?
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Activity 1.5 Crime Scene
Reconstruction
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Importance of striving for objectivity-it is
suggested that the forensic evidence needs to
be evaluated by several individuals throughout
the crime scene investigation.
Crime scene reconstruction personnel should
avoid trying to prove any theory or hypothesis
but should use the processes of deductive
reasoning, inductive reasoning and falsifiability
to create a logical reconstruction of the crime
case.
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References:
1.
2.
Siegel, J.A. (2007). Forensic Science:
The Basics. Florida: CRC Press.
Saferstein, R. (2009). Forensic Science:
From the Crime Scene to the Crime Lab.
New Jersey: Pearson Education, Inc.
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