1. Chapter 1 Criminal Investigation: An Overview1-

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 1-

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 1-

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
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. 1-

5. Other Terms Defined SPECIFIC TERMS Criminalist Forensic science Crime
Felony
Misdemeanor
Continued 1-

6. Other Terms Defined (Continued)
SPECIFIC TERMS
Criminal statute
Ordinance
Elements of the crime
Criminal intent
Modus operandi, or MO 1-

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
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. 1-

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
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. 1-

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 1-

10. Characteristics of an Effective Investigator
SPECIFIC CHARACTER TRAITS
Intellectual
Psychological
Physical
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. 1-

11. An Overview of the 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 1-

12. The Preliminary Investigation: Basic Considerations
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
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. 1-

13. The Preliminary Investigation: Basic Considerations
POINT OF ARRIVAL
Scene may be either utter confusion or deserted
SETTING PRIORITIES
Handle emergencies first
Secure the scene
Investigate
Learning Objective:
Do you know what should be done initially?
Handle emergencies first.
Secure the scene.
Investigate. 1-

14. The Preliminary Investigation: Basic Considerations
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
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. 1-

15. The Preliminary Investigation: Basic Considerations
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 1-

16. The Preliminary Investigation: Basic Considerations
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
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. 1-

17. The Preliminary Investigation: Basic Considerations
CONDUCTING THE PRELIMINARY INVESTIGATION
Questioning
Neighborhood canvass
Measuring, photographing,
videotaping and sketching
Searching for evidence
Processing physical evidence
Recording all statements
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.
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. 1-

18. Crime Scene Investigators
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

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

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

21. Problem-Oriented Policing
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

22. Investigative 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

23. The Investigative Function: The Responsibility of All Police Personnel
SPECIALIZATION NEED
Criminals and their MOs
Investigative techniques
Leaving assigned shifts
Heavy patrol workloads
Increasing efficiency
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. 1-

24. Interrelationships with Others— Community Policing
COMMUNITY POLICING RELATIONSHIPS
Uniformed patrol, dispatchers, prosecutors
Physicians, coroners and medical examiners
Forensic crime laboratories
Citizens, victims, witnesses, media
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. 1-

25. Major-Case Task Forces
COMBINED TASK FORCES
Necessary for many crimes involving drugs, gangs and terrorism
Multidisciplinary approach
Multijurisdictional investigation
Metro crime teams
Special investigation units

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

27. Avoiding Civil Liability
Effective policies and procedures clearly communicated to all
Thorough and continuous training
Proper supervision and discipline
Accurate, thorough police reports
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. 1-

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 1-