2. Introduction
• An observant police officer can initiate an important
criminal investigation
• Criminal investigation combines art and science
• Requires extraordinary preparation and training
• High-tech society
• Citizens expect results more quickly
• Investigators need to step up their technology and
teamwork skills
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3. A Brief History of Criminal Investigation
HISTORICAL SIGNIFICANCE
• Bow Street Runners
• Vidocq Society
• Scotland Yard
• Pinkerton National
Detective Agency
• Major advances in criminal investigation
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4. Criminal Investigation Definitions
KEY DEFINITIONS
• Investigate
Derived from Latin, vestigare, meaning to track or trace
• Criminal investigation
Discovering, collecting, preparing, identifying and
presenting evidence
• Deductive reasoning
Logical process; conclusion follows from specific facts
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5. SPECIFIC TERMS
• Criminalist
• Forensic science
• Crime
• Felony
• Misdemeanor
Continued
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Other Terms Defined
6. Other Terms Defined (Continued)
SPECIFIC TERMS
• Criminal statute
• Ordinance
• Elements of the crime
• Criminal intent
• Modus operandi, or MO
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7. Goals of Criminal Investigations
SUCCESSFUL INVESTIGATIONS
• Determine whether a crime has been committed
• Legally obtain information and evidence to identify the
responsible person
• Arrest the suspect
• Recover stolen property
• Present the best possible case to the prosecutor
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8. Basic Functions of Investigators
INVESTIGATOR FUNCTIONS
• Provide emergency assistance
• Secure the crime scene
• Photograph, videotape and sketch
• Take notes and write reports
• Search for, obtain and process physical evidence
Continued
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9. Basic Functions of Investigators (Continued)
INVESTIGATOR FUNCTIONS
• Obtain information from witnesses and suspects
• Identify suspects
• Conduct raids, surveillances, stakeouts and undercover
assignments
• Testify in court
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10. Characteristics of an Effective Investigator
SPECIFIC CHARACTER TRAITS
• Intellectual
• Psychological
• Physical
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11. An Overview of the Investigative Process
INVESTIGATIVE PROCESS
• Usually initiated by personal observation or information
from a citizen
• Starts with a direction to proceed to a scene
• Department policy defines who responds
• Department policy defines duties of individuals
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12. The Preliminary Investigation:
THE INITIAL RESPONSE
• Suspect may still be at or near the scene
• Injured persons may need emergency care
• Witnesses may still be at the scene
• Dying person may have confession/information
• Weather may change/destroy evidence
• Crime scene may be altered
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Basic Considerations
13. The Preliminary Investigation:
POINT OF ARRIVAL
• Scene may be either
utter confusion or
deserted
SETTING PRIORITIES
• Handle emergencies first
• Secure the scene
• Investigate
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Basic Considerations
14. The Preliminary Investigation:
HANDLING EMERGENCY SITUATIONS
• Sometimes emergencies dictate procedure
• Emergency situations causes the adrenaline to flow
SUSPECT AT OR NEAR THE SCENE
• Policy determines interrogations
• Miranda warning
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Basic Considerations
15. The Preliminary Investigation:
PERSON IS SERIOUSLY INJURED
• Emergency first aid
• Call for medical assistance
• Accompany suspects to hospital
DEAD BODY AT SCENE
• Leave the body as found
• Preserve the scene
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Basic Considerations
16. The Preliminary Investigation:
PROTECTING THE CRIME SCENE
• Major responsibility of the
first officers to arrive
• Locard’s principle of exchange
• Scene is critical
• Maintain security
• Protect from destruction or
alteration from the elements
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Basic Considerations
17. The Preliminary Investigation:
CONDUCTING THE PRELIMINARY
INVESTIGATION
• Questioning
• Neighborhood canvass
• Measuring, photographing,
videotaping and sketching
• Searching for evidence
• Processing physical evidence
• Recording all statements
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Basic Considerations
18. SCIENTIFIC SPECIALIST
• Specialist in organized scientific collection and
processing of evidence
• Processes and packages all physical evidence
• Attends and documents autopsies
• Writes reports and testifies in court
• Crime scene technology degree
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Crime Scene Investigators
19. The Follow-Up Investigation
FACTORS FOR FOLLOW-UP
• Many cases require a follow-up investigation
• Factors exist that are beyond the officers’ control
• Weather can destroy evidence
• Witnesses can be uncooperative
• Follow-up phase builds on what was learned
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20. Computer-Aided Investigation
CRIME ANALYSIS, MAPPING AND GEOGRAPHICAL
INFORMATION SYSTEMS
• Crime mapping and hot spots
DATA MINING
• Sifting through information
• Helps narrow the field of possible suspects
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21. DEPARTMENT-WIDE STRATEGY
• Aimed at solving persistent community problems
• Identify, analyze and respond
• Used in criminal investigations in many ways
• Combining problem-oriented strategies with traditional
investigative techniques
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Problem-Oriented Policing
22. PRODUCTIVITY
• Interest in the police field for some time
• All jobs have some standard of productivity
• Traditional evaluation
Number of cases assigned
Type of case assigned
• Continuous evaluation
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Investigative Productivity
23. SPECIALIZATION NEED
• Criminals and their MOs
• Investigative techniques
• Leaving assigned shifts
• Heavy patrol workloads
• Increasing efficiency
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The Investigative Function:
The Responsibility of All Police Personnel
24. Interrelationships with Others—
COMMUNITY POLICING RELATIONSHIPS
• Uniformed patrol, dispatchers, prosecutors
• Physicians, coroners and medical examiners
• Forensic crime laboratories
• Citizens, victims, witnesses, media
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Community Policing
25. COMBINED TASK FORCES
• Necessary for many crimes involving drugs, gangs and
terrorism
• Multidisciplinary approach
• Multijurisdictional investigation
• Metro crime teams
• Special investigation units
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Major-Case Task Forces
26. Law Enforcement Resources
FEDERAL LAW ENFORCEMENT
• Numerous resources
• Aid local and state agencies
INTERPOL
• International Criminal Police Organization
• Computerized database is available to law enforcement
agencies worldwide
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27. CIVIL LIABILITY
• Effective policies and procedures clearly
communicated to all
• Thorough and continuous training
• Proper supervision and discipline
• Accurate, thorough police reports
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Avoiding Civil Liability
28. Summary
• Determine whether a crime has been committed
• Legally obtain sufficient information and evidence
• Locate and arrest the suspect
• Recover stolen property
• Present the best possible case to the prosecutor
• Cooperation and coordination of efforts are also
required outside the police department
• Criminal investigation is, indeed, a mutual effort
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Editor's Notes
Learning Objective:
Do you know what criminal investigation is?
A criminal investigation is the process of discovering, collecting, preparing, identifying and presenting evidence to determine what happened and who is responsible.
Learning Objective:
Do you know what the major goals of criminal investigation are?
Determine whether a crime has been committed.
Legally obtain information and evidence to identify the responsible person.
Arrest the suspect.
Recover stolen property.
Present the best possible case to the prosecutor.
Learning Objective:
Do you know what basic functions investigators perform?
Provide emergency assistance.
Secure the crime scene.
Photograph, videotape and sketch.
Take notes and write reports.
Search for, obtain and process physical evidence.
Obtain information from witnesses and suspects.
Identify suspects.
Conduct raids, surveillances, stakeouts and undercover assignments.
Testify in court.
Learning Objective:
What do effective investigators do?
Effective investigators obtain and retain information; apply technical knowledge; and remain open-minded, objective and logical. They are also culturally adroit, that is, skilled in interacting across gender, ethnic, generational, social and political group lines.
Learning Objective:
Who usually arrives at a crime scene first?
The initial response is usually by a patrol officer assigned to the area where a crime has occurred.
Learning Objective:
Do you know what should be done initially?
Handle emergencies first.
Secure the scene.
Investigate.
Learning Objective:
Do you know what to do if a suspect is still at a crime scene? Has recently fled the scene?
Any suspect at the scene should be detained, questioned and then released or arrested, depending on circumstances.
Learning Objective:
Do you know how the crime scene and evidence are protected and for how long?
All necessary measures to secure the crime scene must be taken—including locking, roping, barricading and guarding—until the preliminary investigation is completed.
Learning Objective:
What responsibilities are included in the preliminary investigation?
Questioning victims, witnesses and suspects.
Conducting a neighborhood canvass.
Measuring, photographing, videotaping and sketching the scene.
Searching for evidence.
Identifying, collecting, examining and processing physical evidence.
Recording all statements and observations in notes.
Learning Objective:
What the meaning and importance of res gestae statements are?
Res gestae statements are spontaneous statements made at the time of a crime concerning and closely related to actions involved in the crime. They are often considered more truthful than later, planned responses.
Learning Objective:
Who is responsible for solving crimes?
The ultimate responsibility for solving crimes lies with all police personnel. It must be a cooperative, coordinated departmental effort.
Learning Objective:
Do you know with whom investigators must relate?
Using a community policing orientation, investigators interrelate with uniformed patrol officers, dispatchers, the prosecutor’s staff, the defense counsel, supervisors, physicians, the coroner or medical examiner, laboratories and citizens, including witnesses and victims.
Learning Objective:
Do you know how to avoid civil lawsuits?
Effective policies and procedures clearly communicated to all.
Thorough and continuous training.
Proper supervision and discipline.
Accurate, thorough police reports.
