• Describe the criminal investigation process
• Define the chain of custody
• Characterize the myths associated with criminal
• Describe and compare cold cases versus hot
• Compare an interview to an interrogation
• Explain ways to respond to a suspect’s
response, resistance, and lies
Objectives (cont.)
• Articulate the importance of a baseline
• Characterize burden of proof
• Describe strategies to help avoid interrogative
• Explain the tasks of a crime scene analyst
• Characterize police reluctance to use crime labs
• Describe how the literature supports police
reluctance to use crime labs
• Describe the positive effects of the “CSI effect”
• This chapter describes crime scene
investigations, which includes the
investigation process and forensic or
crime laboratory support
• Forensic support has its limitations,
despite the myth that conducting a
successful investigation takes little skill
and that forensics is a cure all.
Criminal Investigation Units
• 90% of all local police departments
have investigative units
• Estimated 15% of all sworn officers are
tasked with criminal investigative
• Federal government maintains a high
profile in many areas of investigative
law enforcement
• FBI agents are primary investigators
Criminal Investigations
• Once a crime has been committed there
are three possible outcomes:
– Crimes goes undetected
– Victim may not report the crime
– Crime comes to the attention of the police
• Investigation is a formal gathering process
that includes interviewing victims,
witnesses, and suspects.
Criminal Investigations (cont.)
• Purpose of Investigation
– Crime control strategy
– Secure the scene through first responders
– Process the evidence
• Process of an Investigation
– Preliminary investigation includes the initial
facts and circumstances
– Continuing investigation is conducted by
detectives with a specialization
Criminal Investigations (cont.)
• Investigators typically follow these steps:
– Request medical service
– Secure the crime scene
– Determine whether a crime was committed
– Make an offer
– Build a case
– Maintain a chain of custody
– Contact the DA
– Conduct a walk-through
Criminal Investigations (cont.)
• Steps (cont.)
– Call specialists
– Bag and tag the evidence
– Take photographs, draw sketches, and use
other forms of documentation
– Create investigative records
– Eliminate “persons of interest”
– Interrogate the suspect
Myths Associated with
Investigators and Investigations
James Bond Syndrome
Myths about Known Crime
Myths about Typical Crime Scenes
Myths about Crime Outcomes
Myths about Prosecution and Solved
• Myths about Hate Crimes
Cold Cases versus Hot Cases
• Hot versus Cold Homicides
– “Hot” homicides following a series of steps in which
investigators build a case and identify a suspect
– If this series of steps does not ensue, the case may
become unsolved (i.e., “cold”)
– Investigators seek to answer:
What happened?
How did it happen?
Who had the opportunity to commit the crime?
Why was the victim killed?
Where did it happen?
When did it happen?
Cold Cases versus Hot Cases
• Cases that most commonly turn cold:
– Missing persons
– Gang- or drug-related killings
– Crimes involving immigrants, transients, and
homeless victims
– Crimes with unidentified victims
– Suicides
– Accidental deaths
– Murder of police officers
Cold Cases versus Hot Cases
• Factors influencing the investigation:
– Time when the crime occurs
– Crime scene locations
– Lack of physical evidence
– Lack of witnesses
– Identification/testimony by witnesses/victims
– Inability to identify victim
– Weapons used
– Gang- or drug-related scenario
Cold Cases versus Hot Cases
• Factors influencing the investigation (cont.):
– Inability to narrow persons of interest
– Inability to identify a person of interest
– Inadequacy of technology to fully analyze the
– Television or newspaper coverage of a crime
– Public perception of criminal act
– Inadequate resource of police department
– Poor interview strategies by detectives
Interviews and Interrogations
• Interview - designed to gather
• Interrogation - process of testing
information and its application to a
particular suspect to obtain a confession
• Interview – no need to inform of rights
• Interrogation – must be informed of
Interviews and Interrogations
• Unable to control environment in
interview because they are often
• Interrogation’s environment and
surroundings are carefully controlled
• In both situations, investigators should
ask good and relevant questions, listen
well, and observe verbal and nonverbal
Interviews and Interrogations
• Interrogation process has 5 objectives:
– Obtain legally valuable facts about the case
– Eliminate the innocent
– Identify the guilty
– Obtain a (legal) confession
– Reduce a suspect’s oral admission to a
permanent form
• Obtaining an admission of guilt requires
that the first 3 are met
Interrogation Rapport
• Provides an opportunity to establish
• Techniques to build rapport:
– Matching your body language
– Maintaining eye contact
– Avoiding judgment
• Interrogators should consider suspect’s
response, resistance, denials, lies
Suspect Response
Suspect resistance
Confession of crime
No comments
Results of polygraph testing
Self-written statements
Self-drawn sketches
Showing and talking about items at the scene of the crime
Reconstruction of the crime event
Denial of crime
Rude jests, comments, body functions
Threats to officers and their families and friends
Suspect Resistance
• Confronting a suspect is a complicated
process that can be described in 7 fears:
– Fear of loss or termination of a job
– Fear of arrest or prosecution
– Fear of embarrassment
– Fear of losing self-image
– Fear of restitution
– Fear of retaliation
– Fear of admitting to the crime
Suspect Denials
• Denial is a survival technique
• Skill of interrogator plays a major role in
moving the interrogation to the ultimate goal
• Environment, suspect, and interrogator all
influence the outcomes of the interrogation
Suspect Lies
• Most chronic offenders lie about
• Accuracy of polygraph is debatable
• May be used to help build a case
• Can provide a focus for investigators
during the interrogation process
Observation of Suspects During
• Micro-expression
– Observation of facial movements and
• Sensory Channels
– Monitor suspect’s vocabulary, articulation,
– Monitor eye movements
– Sensation/feeling channel is where an
investigator can get a confession
Interrogator’s Task and Deception
• Must identify nature of suspects’ deception
• Optimal moment in time when suspect is
most susceptible to making a confession
• Revealing strong evidence too soon might
cause problems:
– Show weaknesses of the case
– Can aid suspect in contradicting or destroying
– Individual might confess to a crime he/she
didn’t commit
Techniques of Interrogation
• Key factor is to determine a baseline –
study the suspect’s normal response to
identify deviations
• Ask questions that cause the suspect to use
different parts of the brain
– Non-threatening questions that require memory
– Questions that require thinking
Techniques of Interrogation (cont.)
Direct, positive confrontation
Theme development
Stopping denials
Overcoming objections
Getting the suspect’s attention
Suspect loses resolve: passive mood
Bringing the suspect into conversation
The confession
Techniques of Interrogation
• Criticism of Interrogation
– Flaw is the expectation that every criminal is
motivated by guilt and lives in constant fear of
– Confessions can emerge as a collaboration
between the investigator and criminal
– Always the possibility of investigator error
– Detectives look for patterns in or draw
inferences from a small number of incidents
Strategies to Help Avoid
Investigative Failure
Rossmo’s strategies
Enhancing the suspect’s self-respect
Changing the detective’s mind
Professional training
Qualifications for Detectives
• A lot of self-discipline, patience, and internalized
• Knowledge of systematic method of inquiry that is
more science than art
• Excellent interview skills
• Initiative and resourcefulness
• Oral and written communication skills
• Knowledge and experience in use of informants
• Strong deductive reasoning skills
• Strong inductive reasoning skills
Qualifications for Detectives
• Good listening skills
• Knowledge of crime scene reconstruction
• Experience in use of computers and report
• Knowledge of courtroom procedures and
• Good health and stamina
• An analytical approach
• Motivation and enthusiasm
Qualifications for Detectives
• Information suspects provide to
investigators is the single greatest driving
force in obtaining a confession and in
conviction of the suspect
• An investigator creates a hypothesis
around the physical evidence of a crime
which allows others to recreate an accurate
view of the scene
• The burden of proof is on the government
Tasks of a Crime Scene Analyst
• Field investigator gathers evidence,
protects chain of custody, transfers
evidence to laboratory personnel
• Chief duty of analyst is to arrange and
collate numerous individual events,
details, and observations
Types of Crime and Analysis
Physical science
Biology unit
Firearms unit
Document examination unit
Photography unit
Toxicology unit
Latent fingerprint unit
Polygraph unit
Voiceprint analysis unit
Police Reluctance to Use Labs
• Massive backlog of unsolved cases
• Slow turnaround time
• DNA is not considered a tool for
investigation by some officers
• Attitudes by officers, institutional support,
personnel, and network all guide
decisions about crime labs
• Different jurisdictions have different laws
and regulations
Criticism of Forensic Science
• Many labs are underfunded,
undercertified, and under attack because
they cannot meet the level of public
expectations or match up to the myths
believed by the public.
• Increase crime lab backlogs can lead to
wrongful convictions
The CSI Effect
• Offers glamour, certainty, self-discipline,
objectivity, truth, and justice all rolled into one
• Raises crime victims’ and jury members’ realworld expectations of investigators and forensic
• Hinders the investigative process
• Literature advises that CSI units cannot
standardize their operations, control their
excessive objectives, or meet judicial
The CSI Effect (cont.)
• Benefits
– Courts have taken an interest
– Stimulates interest in unsolved cases
– Provides understanding when resources are designated to
investigate cold cases
– Encourages those with knowledge of unsolved crimes to come
– Stimulates agencies to become proactive in terms of reviewing
cold cases
– Remind criminals that the case has not been forgotten
– Encourages police to find new ways to serve and protect
– Heightens accountability for police to demonstrate integrity and
Qualifications for Forensic
• College degree for entry level personnel
• Preference given for graduate degree
• A criminal investigation is defined as an
information-gathering process, which includes
interviews among victims, witnesses, and
• The purpose of an investigation is to legally
gather and confirm the evidence; secure the
chain of custody; and identify, arrest, and
obtain a confession from lawbreakers.
• Interviews are fact-finding missions, whereas
interrogations are designed to match acquired
information to a confession
Summary (cont.)
• Because the burden of proof plays an
important role in an investigation, it is up to
the investigators to ensure that the
investigatory process is both legal and logical
• The CSI effect influences criminals, police,
and the public to believe untruths about
forensic science
• The advantage is that the CSI effect has
made police focus on enhancing their
initiatives to detect and apprehend offenders.
• The 'CSI Effect': Does It Really Exist?
• by Honorable Donald E. Shelton
• Crime and courtroom proceedings have
long been fodder for film and television
scriptwriters. In recent years, however,
the media's use of the courtroom as a
vehicle for drama has not only
proliferated, it has changed focus. In
apparent fascination with our criminal
Chapter 11
Crime Scene Investigations