1. Follow-up Investigation
SIX
Follow-up Investigation

2. LEARNING OBJECTIVES
Summarize the factors used to determine whether a follow-up investigation is needed
Outline common internal and external sources of case information
Explain the techniques used in neighborhood and vehicle canvasses
Discuss the role and use of informants
Understand the purpose and objectives of surveillance
Be familiar with the practice of polygraph and psychological-stress evaluators
Describe the methods for conducting photo and live lineups
Explain the guidelines for recording identification results
6-1

3. INVESTIGATIVE SOLVABILITY FACTORS
Can the identity of the suspect/s be established through:
Useable fingerprints being discovered
Significant physical evidence being located
Victims/witness/informant information
A license number of or a significant description of the vehicle known to have been used in the offense
6-2(a)

4. INVESTIGATIVE SOLVABILITY FACTORS (cont'd)
Is there serious physical harm or threat of serious physical harm to the victim
Did the suspect(s) utilize a deadly weapon or dangerous ordinance
Is there a significant m.o. which will aid in the solution of the offense
Is it a sex offense in which the victim and suspect(s) had physical contact
6-2(b)

5. INVESTIGATIVE SOLVABILITY FACTORS (cont'd)
Can a suspect be named
Can a suspect be identified
Can a suspect be described
Is there another reason which leads you to believe that the offense should be assigned for a follow-up investigation
6-2(c)

6. BURGLARY SCREENING DECISION MODEL
One of the more useful tools used by investigators at the onset of their effort is a decision model form.
This allows them to objectively make decisions with regard to how best to proceed with their investigative work.
6-3

7. COMMON INTERNAL SOURCES OF CASE INFORMATION
Incident and supplemental reports
Physical evidence seized
Jail booking reports
Field interview/information reports
Inventories of impounded vehicles
Traffic citations
Crime lab reports
The neighborhood and vehicle canvasses
6-4

8. FIELD INTERVIEW/INFORMATION REPORTS
A field interview/information card (FIR) is filled out when patrolling officers identify persons or vehicles that are suspicious to them but are not connected to any particular offense.
(Source: Courtesy Springfield, Missouri, Police Department)
6-5

9. NEIGHBORHOOD CANVASS
A fundamental aspect of most investigations is the neighborhood canvass
The investigator contacts residents, merchants and others in the immediate vicinity of the crime
A systematic neighborhood canvass soon after the crime may be useful in twenty percent of the cases
The extent of the canvass depends on:
The type of offense
The time of day
The characteristics of the crime scene
6-6

10. NEIGHBORHOOD CANVASS FORM
This form provides the investigator with:
A list of persons contacted
Investigation notes for later analysis
A source of potential leads
(Source: Courtesy Imprimus Forensic Services, LLC)
6-7

11. INFORMATION NEEDED BEFORE CONDUCTING A NEIGHBORHOOD CANVASS
All information relating to the offense
A full description of the suspect
Any injury sustained by the suspect
The type of property taken
6-8(a)

12. INFORMATION NEEDED BEFORE CONDUCTING A NEIGHBORHOOD CANVASS (cont'd)
Possession of these facts is essential for:
Officer’s safety
For the intelligent questioning of possible witnesses
6-8(b)

13. INFORMANTS
Information provided by informants often plays a vital role in a successful investigation
Such information may provide evidence of an unreported crime
Such information may provide the basis for a search warrant
Such information may constitute the basis for an arrest
6-9

14. MAJOR CATEGORIES OF INFORMANTS
Mercenary informant - information provided for financial reward
Rival informant - information provided to establish monopolistic control over activity in question by eliminating a competitor
Plea bargaining informant - information provided to obtain reduced charges or lenient sentence for information
Self-aggrandizing informant - information provided to obtain enhanced sense of self-importance
6-10(a)

15. MAJOR CATEGORIES OF INFORMANTS (cont'd)
Fearful informant - information provided because they are worried they will be endangered by the criminal activities of an associate
False informant - information provided is misleading to direct the investigation away from her/himself, friends, and relatives
Anonymous informants - information provided by an unknown person
Legitimate informants - information provided by a law abiding citizen out of a sense of civic duty
6-10(b)

16. EFFECTIVE USES OF SURVEILLANCE
Establishing the existence of a violation
Obtaining probable cause for a search warrant
Apprehending violators in the commission of illegal acts
Identifying the violators’ associates
Verifying informant reliability
6-11(a)

17. EFFECTIVE USES OF SURVEILLANCE (cont'd)
Providing protection for undercover investigators or informants
Locating persons, places, or things
Preventing crime
Gathering intelligence of individuals and premises prior to the execution of a search warrant
Gathering intelligence on illegal groups' activities
6-11(b)

18. AREA UNDER VIDEO MONITORING
The use of video surveillance camera in public places is becoming common
Such systems may deter crime
Video systems may also gather evidence of a crime
(Courtesy © Scott Iskowitz and Tampa Tribune)
6-12

19. POLYGRAPH EXAMINATIONS
These examinations are used to:
verify, corroborate, or refute statements made by victims, witnesses, and suspects
obtain additional investigative leads
narrow or focus the investigation
eliminate suspects
6-13

20. THE POLYGRAPH
The polygraph is designed to record physiological changes in:
Respiratory rate
Blood pressure and heart rate
Amount of sweat on the fingertips
6-14

21. POSED POLYGRAPH EXAM The polygraph is an investigative tool
It does not substitute for a proper investigation
Only certified, well trained polygraphists should be used
(Courtesy Lafayette Instrument)
6-15

22. The PSE and the CVSA measures voice fluctuations
PSYCHOLOGICAL-STRESS EVALUATOR (PSE) AND COMPUTERIZED VOICE-STRESS ANALYZER (CVSA)
The PSE and the CVSA measures voice fluctuations
These fluctuations can indicate stress.
They can also reveal deception
Recordings of phone conversations can be used in place of personal contact with a suspect
6-16

23. PROCEDURES FOR PHOTO LINEUPS
Include only one suspect in each identification procedure
Select “fillers” (nonsuspects) who generally match the witness’ description of the perpetrator
If multiple photos of the suspect are available, use the one made closest to the time when the crime was committed
Lineups should include a minimum of five fillers
If there are multiple witnesses, consider placing the suspect in different positions each time a lineup shows to a witness
6-17(a)

24. PROCEDURES FOR PHOTO LINEUPS (cont'd)
If a new suspect is developed, avoid using fillers which have been used in a previous lineup for the same witness
Make sure that no writing or information about the suspect's previous criminal history can be seen by the witness
Before the witness views the lineup, check again to make sure the suspect doesn’t unduly standout
Record the presentation order or the lineup and handle the original photographs as evidence
Write a supplemental report which chronologically describes what happened
6-17(b)

25. WITNESS LINEUP IDENTIFICATION FORM
Investigators carefully document witness responses to a live lineup by using this form
Note the names of the witness, the officer, the prosecutor and the defense attorney all appear on the form
(Source: Courtesy St. Petersburg, Florida, Police Department)
6-18

26. RECORDING IDENTIFICATION RESULTS
Proper documentation includes:
check to make sure that all signatures need for the various forms are completed;
collect the information needed to complete standard forms prior to conducting the lineup procedure;
if another witness will have contact with any photographs or forms, make sure that the previous witness has not made any marks or comments on them; and
include in the supplemental report a record of both identification and non-identification results, including any statements as to how sure, or unsure, the witness is
6-19

27. AUTOMATED PHOTO LINE UP
Today investigators may use automated photo-line up programs
Witness descriptions are entered into the computer
The computer searches the database of suspects and persons with similar physical characteristics
(Courtesy of TFP, Inc.)
6-20