INTRODUCTION TO LAW ENFORCEMENT
AND CRIMINAL JUSTICE, 8th Edition
Chapter 7
Specialized Roles of Police
By Henry M. Wrobleski and Kären M. Hess
Specialized Functions of Police
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Investigators
Profilers
Psychics
Intelligence officers
Juvenile officers
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Vice officers
SWAT officers
K-9 assisted officers
Reserve officers
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Investigation
• Investigators must be objective
• Preliminary investigation – first responder
priorities (next slide)
• Discovery crimes (75%) vs. involvement
crimes (25% - rapid response)
• Locard’s Exchange Principle – offender and
crime scene interact with/affect each other
• Solvability factors – witnesses, evidence
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First Responder Priorities
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Initial response/receipt of information
Safety procedures
Emergency care
Secure and control persons at the scene
Boundaries: identify, establish, protect and
secure
6. Turn over control of the scene and brief
investigator(s) in charge
7. Document actions and observations
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Investigative Responsibilities
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Secure the crime scene – contamination
Record all facts related to the case
Photograph/measure/sketch crime scene
Obtain and identify evidence
Protect and store evidence
Interview and interrogate
Assist in identifying suspects
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Photographs vs. Sketches
• Both photographs and sketches of the crime
scene are usually needed
• Photographs:
– include all details
– can show items close up
• Sketches:
– can be selective
– can show much larger areas
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Sample Crime Scene Sketch
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Evidence
Investigators
 recognize,
 collect,
 mark,
 preserve, and
 transport
physical evidence in sufficient quantity for
analysis and without contamination
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DNA
• DNA = deoxyribonucleic acid
• DNA profiling uses the material
from which chromosomes are
made to positively identify
individuals
• No two individuals, except
identical twins, have the same
DNA structure
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Interviewing and Interrogating
• Interview those with information about a
crime:
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Victims
Witnesses
Complainants
Informants
• Interrogate suspects, those believed
connected with a crime
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Identifying Suspects
Basic types of identification:
• Field identification
– at-the-scene
– soon after crime is committed
– based on totality of circumstances
• Photographic identification (e.g., mug shots)
• Lineup identification
• Modus operandi
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Crime Scene Investigation Units
• Some departments have an entire unit to assist in
processing the crime scene
• It provides support services in the form of crime
scene processing, fingerprint identification, and
forensic photography
• The CSU responds to major crime scenes to
detect, preserve, document, impound, and collect
physical evidence
(Weissberg, 2001, p.45)
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Profilers
Detective’s focus:
Height
Weight
Race
Gender
Age
Accent
M.O.
Profiler’s focus:
Personality
Psyche
Pathology
Resultant
behaviors
Profilers develop
more complete
portraits of serial
criminals
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Intelligence Officers
• Undercover assignments
– Ongoing investigations into criminal activity,
such as illegal sale of guns, drug rings,
organized crime
– Risk of entrapment
• Internal Affairs (IA)
– Investigating officers within the department
– Often unpopular with peers and labeled “rat”
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Juvenile Officers
Because juveniles commit a disproportionate number
of local crimes, all officers are juvenile officers
much of the time.
Officers have broad discretion and
may do any of the following:
 Release to parents
 Refer to other agency
 Place in detention
 Refer to juvenile court
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Vice Officers
Vice officers usually concentrate their efforts on
 Illegal gambling (gaming)
 Prostitution
 Pornography
 Narcotics
 Liquor violations
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SWAT Officers
SWAT team officers are
immediately available,
flexible, mobile officers
used to deploy against
any emergency or crime
problem.
They seek to contain and
neutralize dangerous
situations.
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K-9-Assisted Officers
K-9s may be specifically trained in
• Search
• Attack and capture
• Drug detection
• Bomb detection
• Crime deterrence
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Reserve Officers
• Also called auxiliary police
• Patrol in uniform as visible symbol of law
enforcement
• Cannot write citations
• Variety of functions: public education
programs, street patrol, search and rescue
• Used more in smaller, rural agencies
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