CriminalInvestigationCriminalInvestigation

eighth edition

TWO

Investigators, the Investigative Process, and the Crime Scene

WHAT IS A CRIME?

• A crime is the commission or omission of any act, which is prohibited or required by the penal code of an organized political state, to which some punishment or sanction is attached.

• Classifications– Felony

• Punishable by death or imprisonment for more than one year in a state prison.

– Misdemeanor• Punishable by fine and/or imprisonment for up to one year in

a local or county jail.

– Infraction or Violation• Minor offenses punishable by a fine only.

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THE INVESTIGATOR

• Someone who gathers, documents and evaluates evidence.– Strong professional training and experience– Strong degree of self-discipline– Uses legally approved & ethical methods– Strong people skills– Includes all evidence of innocence as well as guilt– Uses systematic methods of inquiry– Uses both inductive and deductive reasoning– Compassionate, not calloused and cynical– Has wide ranging contacts across many occupations– Remains objective at all times– Leaves nothing to chance during investigation

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THE INVESTIGATIVE PROCESS

• Objectives– Establish if a crime was committed– Collect, document and preserve evidence– Identify and apprehend the suspect(s)– Recover stolen property– Assist in the prosecution of the person(s) charged

with the crime(s)

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THE PRELIMINARY INVESTIGATION

• The actions taken at the scene of a crime immediately following its detection and report to the police– Receipt of information and initial response– Emergency care– Crime scene control– BOLO alerts– Crime scene determination– Evidence – The report

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FOLLOW-UP INVESTIGATION

• Subsequent investigation– Contacting witnesses who left the scene– Checking out suspect(s) alibi– Gathering additional evidence from other locations– Talk with informants– Attempt to locate additional witnesses– Evaluate evidence collected and laboratory results of

tests– Obtain search and/or arrest warrants– Recover stolen property– Confer with prosecutor

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CRIME SCENE

• Location where the offense was committed– May include surrounding areas where evidence may

be located– Always start big . . . It’s much easier to make it

smaller than to expand it at a later time– There may be more than one crime scene– Macroscopic versus Microscopic scenes

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ORGANIZATION OF THE CRIME SCENE

• Overall coordination– Handled by assigned case agent– Power to call in additional resources & coordinate all

investigative activities• Technical services

– Crime laboratory personnel & supervisors• Investigative services

– Interviewing witnesses and victims– Neighborhood canvass– Suspect field interrogations

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CATEGORIES OF EVIDENCE

• Corpus Delicti evidence– Evidence that helps to prove the elements of the

crime(s)• Associative evidence

– Evidence that connects the suspect to the scene and/or victim or connects the scene/victim to the suspect

• It is bidirectional

• Trace evidence– Small or microscopic evidence, or evidence in limited

amounts

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EVIDENCE RECOVERY LOG

• A chronological record of who found what evidence, where, witnessed by whom, and notations about other ways the evidence may have been documented, e.g., photography

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EVIDENCE RECOVERY LOG

• The evidence recovery log is an important document which records all pieces of physical evidence found at a crime scene. This is critical if the case is to be successfully prosecuted later.

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CRIME SCENE CONTROL

• The actions which the first arriving officer at the crime scene takes to make sure that the integrity of the scene is maintained

• Control also includes preventing people at the scene from becoming combatants and separating witnesses

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CONCEPTUALIZATION

• Keep known fact AND inferences in mind when processing scene– Facilitates reconstruction of the offense– Identification of the modus operandi– Identification of certain types of evidence– Assists in establishing investigative direction

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CAUTION

• Don’t destroy evidence• Make crime scene bigger than expected and

shrink as necessary• Don’t overlook fruitful areas for exploration• Do more than a cursory examination

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INCLUSIVENESS

• Obtain every piece of evidence• If not sure, take it as evidence until it is ruled out• Do not dismiss items of possible evidence

– Be careful of rationalization and fatigue

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DOCUMENTATION

• Constant Activity– Starts with rough shorthand field notes– Sketches– Diagrams to scale

• WAYS TO DOCUMENT A CRIME SCENE VISUALLY INCLUDE:

• Video taping• Photographing• Sketching

(Courtesy Lewiston, Maine, Police Department)

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THREATS TO INVESTIGATORS HEALTH AND SAFETY AT CRIME SCENES

• Insect bites• HIV/AIDS• Hepatitis B and C • Tuberculosis

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MAJOR CONSIDERATIONS OF THE CRIME SCENE SEARCH

• Boundary Determination • Choice of Search Patterns• Instruction of Personnel• Coordination• Documentation

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CRIME SCENE SEARCH PATTERNS

• The crime scene coordinator may choose from a variety of crime scene search patterns based upon the type and size of the crime scene.

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(a) Spiral

(b) Strip/Line

(c) Grid

(d) Zone/Quadrant

(e) Pie/Wheel