THE INVESTIGATIVE

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CHAPTER 3 (48)

• THE INVESTIGATIVE
• METHOD

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STARTING POINTS

• 1. State the problem
• 2. Form the hypothesis
• 3. Observe and experiment
• 4. Interpret the data
• 5. Draw conclusions

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INVESTIGATIVE ACTIONS

• STATE THE PROBLEM
• Who, what, when, where, why, how
• FORM THE HYPOTHESIS
• Establish Motive, Means, Opportunity
• OBSERVE AND EXPERIMENT
• Evaluate hypothesis, reject if needed
• Interpret results
• Identify suspect

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INVESTIGATIVE ACTIONS (Cont.)

• DRAW CONCLUSIONS
• Stated problem answered
• Evidence support of hypothesis
• Ethics considerations
• Evidence adequate for prosecution
• EFFECT ARREST, RECOVER PROPERTY

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EVIDENCE/HYPOTHESIS

• ALWAYS LET YOUR EVIDENCE DEIVE YOUR
  HYPOTHESIS!!!!!
• YOUR HYPOTHESIS MUST CHANGE
• WHEN EVIDENCE SUPPORTS THE
• CHANGE!!!!!
• THE HYPOTHESIS MUST NEVER DRIVE
• THE INVESTIGATION!!!!!

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HYPOTHESIS

• Construct an explanation for occurrence
• Why this type and particular target?
• How knew locations of valuables?
• WHO HAD MOTIVE, MEANS , AND
• OPPORTUNITY?

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MOTIVE

• That which causes a person to act in a certain
  way.
• Monetary gain is the most likely.
• Murder Ask who would benefit.
• Arson Ask who would benefit.

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MEANS

• Capability of committing the crime
• Who has the tools?
• Who has the knowledge?

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OPPORTUNITY

• Who was present that could have committed the
  crime?
• What was the victim doing that could have put
  him/her into contact with the offender?
• Suspect out of town or in jail
• Suspect has an alibi

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OTHER PHASES

• Observation and experimentation
• Testing hypotheses
• Interpreting data
• ALL THESE ARE SIMULTANEOUSLY WITH THE OTHER
  PHASES
• PUZZLE-Number of pieces? Lack of pieces? Final
  picture?

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GUILTY OR NOT

• Inculpatory evidence serves to prove guilt
• Exculpatory evidence clears or exonerates

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LEGAL GUIDELINES

• Evidence- Anything properly admissible in court
  that will aid the function of a criminal
  proceeding in establishing guilt.
• Admissible means that it can be legally
• used in court.
• Inadmissible means that it cannot be legally
  used in court

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CIRCUMSTANTIAL

• The more physical evidence the better.
• You never have all you need
• If there is anything else, get it.

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TYPES OF EVIDENCE

• DIRECT EVIDENCE
• Will normally prove a fact without other
  support. Testimonial
• INDIRECT EVIDENCE
• All physical evidence is CIRCUMSTANTIAL.
• It puts the suspect at the crime scene.
• It does not prove guilt in itself.

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PHYSICAL EVIDENCE

• Real evidence, physical, tangible items
• May be trace evidence- forensic, needs analysis
  
• Fingerprints
• Hairs
• Fibers
• Blood
• DNA- Deoxyribonucleic acid

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SUITABILITY

• EVIDENCE MUSTBE COMPETENT
• Has qualities that make it trustworthy or
  reliable. Question who is reliable?
• RELEVANT
• Relates directly to the case
• MATERIAL
• Logical connection and helps find truth

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EXCLUSIONARY RULE

• Illegally obtained evidence cannot be used in
  court. Applies to violations of Constitutional
  rights
• Weeks v. US
• Mapp v. Ohio

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EXCEPTIONS

• HEARSAY
• Confessions to an investigator
• Dying declarations
• Res Gestae statements
• Judicial notice
• Testimony of a female under 14 yr. who is a
  victim of a sex crime

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RULE OF DISCOVERY

• Allows the defendant, through his attorney, to
  examined documents, reports and other information
  in possession of the police or prosecution
• Prosecution must give up everything
• Lose your case in a suppression hearing

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PROBABLE CAUSE

• 4th Amendment
• ARREST- A reasonable person would believe that a
  crime has or will be committed and the person to
  be arrested committed or will commit the crime.
• SEARCH- A reasonable person would believe that a
  crime has or will be committed and evidence of
  the crime will be found in the place to be
  searched

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SEARCH WARRANT

• THREE PARTS
• AFFIDAVIT
• WARRANT
• RETURN

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EXCEPTIONS

• REQUIRES SAME PROBABLE CAUSE
• WARRANTLESS SEARCH IS UNCONSTITUTIONAL ON ITS FACE

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EXCEPTIONS

• Exigent circumstances
• Stop and frisk
• Search incident to arrest
• Custodial
• Plain view
• Vehicle
• Border

• Open fields
• Abandoned property
• Consent
• Administrative
• Probation search
• Protective sweep

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BURDEN OF PROOF

• CRIMINAL CASE- Beyond a reasonable doubt-
  continuous demonstration of guilt
• 99 percent sure
• CIVIL CASE- A preponderance of the evidence-
  whoever has the best case
• 50 percent sure

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CORPUS DELICTI

• BODY OF THE CRIME- The fact necessary to prove
  that a crime was committed.
• All the essential ELEMENTS of an offense
  constitute the corpus delicti
• Investigator must know all the elements of every
  crime and be able to prove each beyond a
  reasonable doubt

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PHASES OF CRIMINAL INVESTIGATION

• PRELIMINARY INVESTIGATION
• IN-DEPTH INVESTIGATION
• CONCLUDING INVESTIGATION

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PRELIMINARY

• Offense determined
• Suspect arrest if he is on scene
• Protect crime scene
• Victims and witnesses identified

• Basic statements taken
• Crime scene processed- by investigator

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IN-DEPTH INVESTIGATION

• Preliminary inv. Data re-examined
• Crime scene re-visited
• Additional crime scene processed- May need to get
  another search warrant

• All victims and witnesses interviewed
• Documents processed
• Facts and evidence gathered
• Criminalistics arranged- forensic work

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CONCLUDING INVESTIGATION

• Case is suspended
• Case is prepared for prosecution

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CLEARANCE RATES

• VIOLENT CRIMES
• Murder 61
• Aggravated assault 54
• Forcible Rape 41
• Robbery 25

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CLEARANCE RATES

• PROPERTY CRIMES
• Burglary 13
• Larceny-theft 17
• Motor vehicle theft 13
• Arson 17

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SUCCESSFUL INVESTIGATIONS

• 1. Are there witnesses?
• 2. Is there a suspect?
• 3. Can police locate the suspect?
• 4. Is there a description (photo)?
• 5. Can police make identification?
• 6. Can a suspect vehicle be identified?
• 7. Is stolen property traceable?

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SUCCESSFUL INVESTIGATION

• 8. Is there a clear modus operandi (MO)?
• 9. Is there significant physical evidence?
• 10. Is there a positive report of physical
  evidence by a trained investigator?
• 11. Is it reasonable to expect the case to be
  cleared?
• 12. Is it likely that anyone but the suspect
  committed the crime?

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IN-DEPTH/ CONCLUDING INVESTIGATION

• SEE P. 62 IN TEXT FOR ACTIVITIES OF THE IN-DEPTH
  INVESTIGATION
• SEE P. 63 IN TEXT FOR ACTIVITIES OF THE
  CONCLUDING INVESTIGATION

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ARREST/ PROSECUTION

• SEE P.64 FOR THE TYPICAL OUTCOME OF 100 FELONY
  CRIME INVESTIGATIONS

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SEARCH WARRANT

• SEE SEARCH WARRANT EXAMPLE