MODULE #2 Flashcards
factors that affect eyewitnesses’ performance (2)
(1) Estimator variables
(2) system variables
estimator variables (2)
(1) factors that may affect eyewitness testimony and that are not under the control of the criminal justice system
(2) These variables have to do with the characteristics of the eyewitness or the circumstances surrounding the event witnessed.
system variables
factors that may affect eyewitness testimony and that are under the control of the criminal justice system
Examples of estimator variables (4)
- the emotional state of the eyewitness,
- the amount of attention an eyewitness paid to the event and to the perpetrator,
- the length of time an eyewitness viewed a perpetrator,
- the lighting conditions under which a perpetrator was viewed
Examples of system variables (2)
- the way an interview is conducted o
- the way a lineup is constructed
three stages in memory processing
(1) encoding,
(2) storage, and
(3) retrieval
Encoding (5)
(1) Not all event details are encoded.
(2) When we encounter an event, we selectively attend to and encode a subset of event details.
(3) Selective attention is particularly relevant when the event is complex and extensive, as more details are selected out of attention, resulting in a memory trace that is incomplete.
(4) we don’t simply passively encode stimuli in the environment; we actively interpret our experiences.
(5) Expectations that are formed long before an event occurs may predispose us to remember the event in certain ways.
Storage (6)
(1) Information about a past event is not stored in a veridical videotape-like manner that we can access whenever we need to; it is a compilation of information from a variety of sources that combines to allow us to “know” what occurred at some past time.
(2) information acquired before and after the event influences what we report remembering about the target event
(3) General knowledge that is acquired before an event is experienced can also influence what information is stored in memory
(4) For instance, we tend to use general knowledge to “fill in the blanks” when details in memory are incomplete.
(5) may also use general knowledge to change information that is inconsistent with expectations
(6) we have trouble remembering what we actually perceived versus what we reported having perceived. This could lead to inaccuracies if the prior reports contain errors.
eyewitness’s suggestibility
the tendency of eyewitnesses to be easily influenced by suggestion
eyewitness’s suggestibility
the tendency of eyewitnesses to be easily influenced by suggestion
Retrieval (3)
- the type of question asked during retrieval attempts may have a substantial impact on what is recalled
- The nature of a retrieval cue will affect the kind of information that is retrieved
- A retrieval cue on one occasion may activate a different subset of details than a different retrieval cue that is administered on another occasion.
Situational Factors That May Affect Eyewitness Identification
- Stress/Arousal
- Weapon Focus
Generally, we recall the gist and central elements of emotional events more accurately than we do the gist and central features of non-emotional events. There are at least four possible reasons for this:
(1) events are emotional because they relate to things or include details that we care about, and this leads to better memory for those details;
(2) we tend to rehearse arousing events more than neutral events, and rehearsal enhances memory;
(3) arousing events may activate amygdala-based processing that leads to particularly vivid memories (not necessarily accurate, but memories that are experienced as vivid);
(4) there is a narrowing of attention to the central details of events that are arousing, leading to good memory for the central details at the expense of memory for peripheral details.
Stress/Arousal (2)
- emotional arousal as a physiological response and stress as the subjective interpretation.
- an event is emotionally arousing and an individual subjectively interprets that arousal as negative (stressful) or not (not stressful).
Easterbrook hypothesis
states that as arousal increases, attention to the most salient elements of the event is sharpened at the expense of attention to the less central elements of the event.
Reisberg and Heuer (2007) suggest that the narrowing of attention may not be entirely due to arousal. (2)
- Part of the effect could be explained because the central details of emotionally arousing events are typically unusual in some way, and unusual details command attention.
- Because we have limited attentional resources, some attention is diverted from peripheral details to the central details, leading to improved memory for the central details and impoverished memory for peripheral details.
There are two possible explanations for weapon focus phenomenon (3)
- the presence of a weapon is stressful and frightening to witnesses, and as a result their memory is impaired
- the weapon draws people’s attention because it is unusual or unexpected. We don’t typically encounter people carrying guns in our everyday lives. Thus, our attention is drawn to the weapon and this impairs memory for other details.
- Related to this point, when there is a weapon used in the crime, it would make sense for people to pay attention to where the weapon is pointed to assess their level of danger. As a result, witnesses do not look at the assailant’s face as frequently and later on have more trouble identifying who the real criminal was.
Weapon Focus (3)
- Research has shown that eyewitnesses are significantly influenced by the visual presence of a weapon.
- When a weapon, such as a knife or gun, is present, witnesses’ memory for other details is impaired
- eyewitnesses narrow their attention, spending more time focusing on the weapon and less time on other aspects of the situation, including the physical characteristics of the event and the perpetrator
weapon focus effect
the phenomenon whereby a witness’s memory for details is impaired by the presence of a weapon
Post-Event Factors That May Affect Eyewitness Identification
- Passage of Time
- Misleading information
Misleading information (6)
- can affect the accuracy of an eyewitness’s recall
- reports of eyewitnesses can be influenced by information introduced after the event.
- suggestions implanted within questions can influence the recall of eyewitnesses
- the way in which questions are worded could also influence eyewitness recall
- subtle variations in wording or subtle suggestions implanted in a question or statement about an event can result in substantial variation in the eyewitness’s recall of the event
- There is an interaction between passage of time and suggestion. The more time that passes between a witnessed event and a misleading question or other attempt to implant a suggestion, the more effective the suggestion will be in distorting the accuracy of the eyewitness’s report
Wells, Wright, and Bradfield (1999) delineated three conditions under which misleading information tends to affect the accuracy of eyewitness accounts:
(1) when the strength of the original memory trace is weaker rather than stronger (such as when an eyewitness does not get to observe the event for very long, or when a great deal of time has passed since the event);
(2) when the misinformation is not recognized as being incorrect at the time (such as when the misinformation is about a peripheral detail rather the central gist of the event);
(3) when the misinformation is delivered by a credible source (such as a police officer).
Three explanations for the suggestibility effect have been offered
- Misinformation Acceptance
- Source misattributions
- Memory impairmment
Misinformation Acceptance (2)
- This is the process in which participants guess or respond in a way they think the questioner wants them to respond.
- Because the questioner presented the misinformation or otherwise expressed a desire to hear the misinformation, it seems reasonable to participants that the suggestion is the desired response.
Source Misattributions:
Participants recall both the experienced detail and the suggested detail but cannot remember how each detail was learned, and sometimes inaccurately attribute the suggested detail to the experience.
Memory Impairment
The misinformation impairs participants’ ability to remember the experienced details (that is, it either renders the experienced detail inaccessible or destroys/alters it).
General Principles for Interviewing Witnesses (5)
- Begin the interview by developing rapport with the witness
- Remain neutral and objective.
- Ask open-ended questions that become more structured only if necessary and only as the interview progresses.
- Avoid the use of leading (or misleading) questions.
- Allow the interviewee to control the interview
Two important goals of beginning the interview by developing a rapport
- the witness is being asked to work hard to provide a detailed description of an unpleasant experience to a stranger (the police officer) who is assumed to be an expert on crime. This request will be more successful if the police officer can reduce some of the stress by developing rapport.
- rapport building is also a first step in transferring control of the interview to the witness.
Remain neutral and objective.
Interviewers must not direct the dialogue or reveal their biases.
ways interviewers can inadvertently introduce their beliefs about the event to the witness: (4)
- by selectively reinforcing responses that are consistent with their hypothesis, verbally and non-verbally;
- by ignoring or otherwise discounting statements that are inconsistent with their biases;
- by asking leading questions; and
- by taking control of the interview.
Open-ended questions are recommended for a number of reasons. (3)
- cognitive resources are limited, and if witness resources are taken up listening to the questions (and, perhaps, trying to figure out what the interviewer wants to hear), fewer resources are available to search memory.
- interviewers may not have the cognitive resources needed to listen carefully to the witness if they are thinking about the next question.
- interviewers avoid the problems associated with closed questions.
What is wrong with closed questions? (4)
- The information obtained is likely to be limited.
- asking closed questions discourages witnesses from offering unsolicited information, because they believe the interviewer is only interested in the answers to the specific question.
- Closed questions may foster compliance, with witnesses guessing or providing answers that are consistent with what they think the interviewer wants to hear.
- witnesses may modify subsequent reports so they are consistent with their previous responses to the closed question
Avoid the use of leading (or misleading) questions.
Closed questions are more likely than open questions to contain misleading information, and this could contaminate and compromise subsequent testimony.
Allow the interviewee to control the interview (4)
- The interviewer should talk 20 to 30 percent of the time, and the interviewee should talk 70 to 80 percent of the time.
- Witness should be allowed to provide uninterrupted responses and encouraged to say everything that comes to mind-whether or not it seems trivial or irrelevant
- witnesses should be cautioned not to guess or make anything up.
- Interviewers cannot know all forensically relevant details of a past crime. If the police do not allow witnesses to report all that they can recall about a particular detail, important information may not be elicited (e.g., tattoo, scar, accent).
The Enhanced Cognitive Interview (ECI)
a method of interviewing witnesses to enhance the correct recall of information
ECI relies on two principles
- feature overlap
- multiple retrieval paths
feature overlap
states that effective memory retrieval is related to the degree of similarity (overlap) between the retrieval cue and the original event (also known as encoding specificity)
multiple retrieval paths
recognizes that there are several retrieval paths to an encoded event; if all of the relevant information is not available with one retrieval cue, more information may be available with another retrieval cue.
The ECI is based on four memory-retrieval methods designed to increase recall
1.The witness is asked to reinstate the context of the crime
2. The witness is told to report everything.
3. The witness is asked to report the crime in a variety of orders
4. The witness is asked to report the crime for multiple perspectives
The witness is asked to reinstate the context of the crime (4)
- helps witnesses maximize the amount of overlap between the encoding and retrieval contexts.
- Witnesses are guided to reconstruct the context, including surroundings, emotions, and thoughts.
- It may help to ask them to close their eyes when recalling the crime
- most effective when there is a delay between the crime and the interview
The witness is told to report everything
- Witnesses are instructed to include everything in the report, even partial details and details that seem irrelevant.
- When this prompt is administered, they should be reminded not to guess or make anything up.
The witness is asked to report the crime in a variety of orders (3)
- to report the event in a variety of orders and to report the event from a variety of perspectives.
- Witnesses may, for instance, be asked to report the event from the end to the beginning or from the most memorable point to the end.
- they may be asked to describe the event from a different spatial location (e.g., “What would you have seen if you had been standing across the street?”) or from a different person’s perspective.
The witness is asked to report the crime for multiple perspectives (3)
- Witnesses are asked to imagine what the crime would have looked like from another person’s perspective, such as the perpetrator’s or another witness’.
- They may also be asked to think about what the crime would have looked like from another vantage point, such as from up above.
- This is meant to increase recall.
directs police to use witness-compatible questioning (2)
- Retrieval is most likely to be successful if the details reported are consistent with a witness’s current mental record. So if witnesses are currently thinking about the perpetrator, it is not a good idea to ask about the getaway car.
- First, a question about the getaway car is likely to end their mental record of the perpetrator, perhaps before they have reported all they can recall about the perpetrator. Second, they may answer questions about the getaway car before they have an ideal mental record of it.
reasons live lineups are rare in Canada (7)
(1) the real inconvenience of constructing an adequate live lineup, particularly in smaller communities, where the number of foils (i.e., members of the lineup other than the suspect) that are unknown to the witness is limited;
(2) the suspect has a right to refuse to participate in a live lineup or to request that counsel is present during the lineup procedure (however, the police can conduct a photo lineup or a video lineup without consent of the suspect
(3) photo lineups are less time-consuming to prepare;
(4) photo lineups are portable, making them much more convenient;
(5) photo lineups are static, so the police do not have to be concerned with the behaviour of any member of the lineup that could introduce bias;
(6) the witness may be less anxious about examining a photo lineup than a live lineup; and
(7) all witnesses see the same photo.
Estimator Variables that Affect Eyewitness Identification Accuracy (5)
- passage of time,
- the environment
- duration of the event,
- the race of individuals involved, and
- unconscious transference
Passage of Time (4)
- As with any memory, recall drops off as time passes
- the rate of forgetting is steepest immediately after the event and then levels off
- amount of time that passes between the event witnessed and the opportunity to describe the event or make an identification will decrease the accuracy of an eyewitness account
- eyewitnesses forget things over time and, therefore, accuracy diminishes as more time passes
Environmental Factors (3)
- amount and type of light available at the crime scene affect how well eyewitnesses are able to see and, therefore, how well they are able to perceive the events as they unfold
- distance between the witness and the observed event
- the presence of additional simultaneous activity or other distractors
Duration of Event (3)
- Research on facial recognition suggests a positive relationship between time and accuracy such that the longer witnesses are exposed to a perpetrator, the more accurate their eyewitness testimony will be.
- There is a tendency for people to overestimate the duration of brief events and underestimate the duration of lengthy events.
- witnesses tend to overestimate the amount of time they were exposed to the perpetrator.
- if the perpetrator has a weapon, witnesses will spend even less time observing facial and physical features.
Cross-Race Identification (2)
- there is evidence to suggest that people are better at recognizing the faces of members of their own race than they are at recognizing the faces of members of other races.
- as our contact with members of different racial groups increases, our ability to recognize faces from those racial groups improves.
own-race bias
the phenomenon whereby within-race identifications are significantly more likely to be accurate than cross-race identifications
Unconscious Transference (2)
- inaccurately attributing a face to a different context
- unconscious transference occurs when an eyewitness mistakenly identifies an innocent bystander who was present at the crime scene as the perpetrator
Construction and Administration of lineups
- The belief that the suspect is the culprit increases substantially once that suspect has been selected from a lineup
target-present lineup
If the suspect is the culprit, the lineup is said to be a target-present lineup.
target-absent lineup
If the suspect is not the culprit (e.g., the police made a mistake), the lineup is said to be a target-absent lineup.
Wells and colleagues (1999) identified three broad domains as sources of eyewitness identification errors in lineups that could lead to an incorrect identification of an innocent suspect:
- instructions
- structure
- procedure
Pre-Identification Instructions (5)
- If police instruct the witness prior to viewing the lineup that the perpetrator might or might not be present, inaccurate or false identifications can be reduced substantially.
- instructions to witnesses should include a warning that they are not to guess.
- Asking a witness to select a perpetrator from a lineup places a high degree of demand on the witness
- many will select the individual who most closely approximates the perpetrator.
- Most witnesses feel a desire to assist the police and, therefore, experience psychological pressure to identify someone from the lineup as the perpetrator.
Structure of the Lineup (5)
- lineup should contain only one suspect
- All other members of the lineup (i.e., the foils) should be known innocents
- there should be nothing about the suspect that makes him or her stand out from the foils.
- On the other hand, if the foils look too much like the suspect, it will be impossible to make an identification.
- foils are selected by matching them to the description of the perpetrator.
Administration of the Lineup (2)
- Sequential presentations tend to encourage absolute judgments,
whereas simultaneous presentations tend to encourage relative judgments. - sequential presentation was superior to simultaneous presentation.
relative judgment
involves comparing lineup members to one another and choosing the one who looks most like the culprit.
absolute judgment
involves comparing a lineup member with memory of the perpetrator and deciding if the lineup member matches the memory record.
False identifications in target-absent lineups are more likely to occur when?
when the witness adopts a relative judgment strategy rather than an absolute judgment strategy (a sequential superiority effect).
blank lineup (2)
- lineup in which every member is known to be innocent of the offence in question
- the use of a blank lineup can help to weed out those eyewitnesses who are prone to make mistakes.
the experimenter expectancy effect (2)
- occurs when test administrators (in)advertently express their opinion and influence responses
- participants can pick up on the nonverbal cues of an experimenter and can alter their behavior accordingly
To avoid the experimenter expectancy effect:
the officer administering the test should be blind to the identity of the suspect.
Witness Confidence (5)
- Research indicates that highly confident witnesses are persuasive with jurors.
- confidence is not necessarily related to accuracy
- Highly confident witnesses may be inaccurate while less confident witnesses may be accurate.
- research indicates how easily witness confidence can be manipulated.
- If more variables are present that influence confidence but not accuracy, the confidence-accuracy relationship will be weaker
Why is the relationship between confidence and accuracy uncertain?
(5)
- Research indicates that confidence is highly malleable and can be affected by factors that either do not affect accuracy or that affect accuracy in opposite ways.
- Confidence increases over time; accuracy decreases over time.
- Confidence increases if positive feedback is given; accuracy does not.
- Confidence increases the more times a witness is questioned; accuracy may not.
- Successive identifications increase the confidence of witnesses, which, in turn, increase their persuasiveness but not their accuracy.
Safeguards and Protections
can be used to decrease the chances that innocent people will be mistakenly identified, and if they are identified, that they will not be convicted of a crime.
safeguards or protections fall into two main categories:
- (investigation procedures) those that can be implemented during police investigation procedures, especially lineups, and
- (courtroom procedures) those that can be implemented within the courtroom.
Researchers have offered recommendations that would serve to reduce the number of mistaken identifications in lineups.
- Who conducts the lineup
- Instructions on Viewing
- Structure of Lineup or Photo Spread
- Obtaining Confidence Statements
- Videotaping the Lineup and Witness Identification
Rule 1: Who conducts the lineup
the person who conducts the lineup or photo spread should be blind as to which member is the suspect.
Rule 2: Instructions on Viewing (2)
- eyewitnesses should be told explicitly that the person in question might not be in the lineup or photo spread and therefore should not feel that they must make an identification.
- They should also be told that the person administering the lineup does not know which person is the suspect in the case
Rule 3: Structure of Lineup or Photo Spread
- the suspect should not stand out of the lineup or photo spread as being different from the distractors based on the eyewitness’ previous description of the culprit or based upon other factors that would draw extra attention to the suspect
Rule 4: Obtaining Confidence Statements (3)
- a clear statement should be taken from the eyewitness at the time of the identification and prior to any feedback as to his or her
confidence that the identified person is the actual culprit. - the only way to accurately assess eyewitnesses’ confidence in the
identification is to ask for their confidence level at the time of the identification. - any significant discrepancy between the level of confidence indicated by the eyewitness at the time of the identification and during testimony at trial can be noted by the jury and considered accordingly.
Rule 5: Videotaping the Lineup and Witness Identification
allows for an objective record of the structure of the lineup, the person conducting the lineup, and the instructions used, and the length of time that an eyewitness took to make the identification, as well as his or her confidence in the identification
Courtroom Procedures (2)
- educate the jury about the factors that may impact the accuracy
of an eyewitness’s testimony. - Aside from cross-examining eyewitnesses in an attempt to bring to light possible weaknesses in their testimony, the defence can educate the jury about some of these factors in two other ways: expert testimony about eyewitness testimony and judicial instructions
Expert Testimony (3)
- Psychologists may be called as experts to testify about eyewitness testimony.
- this type of testimony focuses on the factors that may impact the accuracy of eyewitness testimony in an attempt to educate the jury about the possibility of false or mistaken testimony.
- psychologists will explain the research on eyewitness testimony to the judge or to the jury but will not comment on the accuracy of the particular witness.
Judicial Instructions
An alternative to expert testimony is for the judge to provide instructions to the jury to alert them to some of the limitations of eyewitness identification
The stages of memory (5)
- Perception/Attention Stage
- Encoding Stage
- Short-term memory
- Long-term memory
- Retrieval stage
Perception/Attention Stage
we notice something in our environment that is worth paying attention to
Encoding Stage
you take this information in for a short period of time and then if you decide that it is worth memorizing, you place it into your Short-term memory store.
Short-term Memory
has a limited capacity and we don’t always take all of the information that we encoded into our short-term memory.
Long-term memory (2)
- If we don’t keep thinking about a piece of information or actively trying to remember it, it may not pass from our short-term memory into Long-term Memory.
- putting information into long-term memory is not easy. It takes a lot of effort to remember information.
Retrieval stage
Long-term memory is a longer holding facility and once you have stored the information in long-term memory it can be retrieved at a later date
Eyewitness memory can be partitioned into two types of memory:
- Recall memory
- Recognition memory
Recall memory (2)
- involves a witness reporting the details of an event they saw occur.
- For example, if they were asked to describe what the suspect looked like or what they did during the crime.
Recognition memory (2)
- involves deciding whether a previously seen person is the same as what is currently being viewed.
- For example, looking at a photograph of a potential suspect to determine if they committed the crime.
foils or distractors (4)
- are lineup members who are known to be innocent of the crime in question.
- The investigator wants to test the hypothesis that one specific suspect committed the crime, not use the lineup as a fishing expedition to find a possible perpetrator amongst a group of known criminals.
- the lineup should include foils who are similar to the suspect in terms of race, height and other identifying characteristics.
- The investigator wants to make a positive identification (if given) as valid as possible and not introduce any bias into the lineup procedure.
Investigators should make every effort possible to create a fair lineup.
This is a lineup where the suspect does not stand out from the other lineup members in some way.
There are 2 basic methods for conducting a lineup
simultaneous lineup or a sequential lineup
simultaneous lineup
all the lineup members are shown at once to a witness
sequential lineup (2)
- Involves showing each lineup member one a time to the witness and having the witness say “yes” or “no” to each one
- The witness has to make a decision about whether the person they are looking at is the perpetrator before moving onto the next person.
Compare simultaneous lineup and a sequential lineup (7)
- Researchers have found that when people are shown a simultaneous lineup, they engage in something called a relative judgment.
- Most witnesses think that the culprit is in the lineup, so they look at all of the people in the lineup and decide who looks MOST like the person they saw.
- This can definitely lead to false identifications, especially if the police haven’t arrested the right person and the real criminal isn’t in the lineup.
- Sequential lineups, in contrast lead to absolute judgments.
- In an absolute judgment, the witness compares each lineup member to their memory of the perpetrator to decide if that person is the perpetrator.
- Researchers have found that the sequential lineup is superior to the simultaneous lineup.
- Witnesses are far less likely to choose an innocent person from the lineup with the sequential method than the simultaneous method.
Research on the Enhanced Cognitive Interview (ECI) has found that:
using ECI results in a 35% increase in the amount of correct information reported compared to a standard police interview, and a small increase in the amount of incorrect information reported.
The research on facial recognition suggests a positive relationship between time and accuracy such that the longer a witness is exposed to a perpetrator, the __________________ his or her eyewitness testimony (Memon, Hope, & Bull, 2003).
more accurate
criminal profiler (2)
- is an investigator or psychologist who looks at evidence from the crime scene, delves into the victim’s background and potential relationship to the perpetrator and examines witness accounts of the crime to develop a description of the person or people who committed the crime.
- They use all of this information to generate hypotheses about the type of person who committed the crime and then search for specific people who have these characteristics.
the most important trait that a profiler can possess (2)
- Attention to detail
- the profiler also has to be able to synthesize multiple cues to identify crime patterns
the criminal profile generating process involves the following 5 steps:
- An in-depth study of the nature of the crime and the sorts of people who have committed offenses like the current one in the past.
- A comprehensive analysis of the crime scene itself (including the primary crime scene where the crime was committed and the disposal site, if it is a different location from the primary crime scene)
- A detailed investigation into the victim or victim’s background and activities
- A formulation of potential motivating factors for the offender and victim(s)
- The creation of a description of the offender based on characteristics from the crime scene and past criminals’ behaviour
At the end of this step-by-step process, the profiler would have developed a profile that follows a standard format, including predictions about : (9)
the offender’s age, sex, race, level of educational, marital status, habits, family characteristics, type of vehicle and any indications of psychopathology.
Modus Operandi (2)
- is what an offender has to do to accomplish a crime.
- It’s learned behaviour and gets modified and perfected as the criminal gets better and better at what he does.
Signature (3)
- is something the offender has to do to fulfill himself emotionally.
- It’s not needed to successfully accomplish the crime, but it is the reason he undertakes the particular crime in the first place.
- something that is special (possibly even unique) to that particular offender
Typologies (2)
- are a group of personality and background characteristics that are linked to specific types of crimes.
- A profiler would look at things like motivation, type of victim, method used to commit the offense and crime scene evidence to group these typologies together.
Organized killers (3)
- killers carefully select their victims and plan the murder well.
- They show signs of self-discipline at the crime scene by leaving few clues.
- They are more likely to use rituals involving torture and dismemberment.
disorganized killers (3)
- Choose their victims randomly.
- They act impulsively and behave haphazardly during the crime.
- They are more likely to use whatever weapon they can find.
Visionary types:
serial killers who have experienced a psychotic break from reality and believe that voices are instructing them to kill
Mission-oriented types
serial killers who are focused on the act of murder itself and have an urge to kill people they think are evil
Hedonistic types:
serial killers who kill for the thrill of it. They get pleasure from torturing their victims
Power-oriented types:
serial killers who are motivated by a need for dominance and who enjoy capturing and controlling their victim before killing them
serial killers-murderers (7)
- who kill three or more people in separate events, with a cooling-off period between murders.
- Many have experienced some combination of physical, sexual, and/or psychological abuse during childhood.
- Maladjustment during their childhood sometimes expresses itself in cruelty toward animals.
- Nearly all serial killers are white males and are typically of average intelligence,
- Most seek to dominate their victims before killing them. They tend not to kill using guns, preferring more intimate methods such as strangulation, stabbing, or even torture. Before killing, they often drink alcohol or use other drugs, perhaps to desensitize themselves and to lower inhibitions.
- They tend to select victims of a particular type
- often show an obsessive interest in violent pornography and serial killing is often a highly sexualized crime.
signature aspect of the crime (2)
- the distinctive, personal aspect of the crime that presumably reveals the personality of the killer (e.g., a particular form of torture used or a particular sexual activity).
- the methods used to abduct, transport, or dispose of victims may change, but the signature will remain relatively constant because it is “why he does it: the thing that fulfills him emotionally … the emotional reason he’s committing the crime in the first place
the first systematic profile offered to assist police in a criminal investigation
Jack the Ripper
Organized Crime Scene (9)
- Planned crime
- Controlled conversation with victim
- Scene reflects control
- Demands submissive victim
- Restraints used
- Aggressive prior to death
- Body hidden
- Weapon/evidence absent
- Transports victim
Disorganized Crime Scene (9)
- Spontaneous crime
- Minimal conversation with victim
- Scene is random/sloppy
- Sudden violence to victim
- Minimal use of restraints
- Sex after death
- Body left in view
- Weapon/evidence present
- Body left at scene
Hypothesized Characteristics of Organized Murderers (9)
At least average in intelligence
Interpersonally competent
Prefers skilled work
Sexually competent
Inconsistent childhood discipline
Controlled mood during crime
Precipitating situational stress
Follows media accounts of his crime
High geographic mobility
Hypothesized Characteristics of Disorganized Murderers (9)
Below average in intelligence
Interpersonally incompetent
Prefers unskilled work
Sexually incompetent
Harsh childhood discipline
Anxious mood during crime
Minimal situational stress
Minimal interest in news media
Lives/works near crime scene
became an enormously influential tool for creating profiles. (3)
- the organized-disorganized crime scene taxonomy led directly to inferences about the personality and circumstances of a killer.
- simplistic, two-part taxonomy, with its long inferential leaps from crime scenes to personality traits, became an enormously influential tool for creating profiles.
- organized versus disorganized distinction became the great divide, a fundamental way of separating two quite different types of personalities who commit multiple murders
differentiated classification scheme later proposed by Ronald
Holmes and his colleagues
examined the characteristics of known serial killers and found that most could be grouped into one of four types: visionary, mission-oriented, hedonistic, and power-oriented
differentiated classification scheme later proposed by Ronald
Holmes and his colleagues (2)
- examined the characteristics of known serial killers and found that most could be grouped into one of four types: visionary, mission-oriented, hedonistic, and power-oriented
- the scheme offers some insight into the varied motives behind these hideous crimes
earlier approaches for profiling offenders who commit sexual homicide involved characterizing the crime based on its function for the offender. Four types of functions were conceptualized:
- power-assertive,
- power-reassurance,
- anger-retaliatory, and
- anger-excitation.
earlier approaches for profiling offenders who commit sexual homicide involved characterizing the crime based on its function for the offender. Four types of functions were conceptualized:
- power-assertive,
- power-reassurance,
- anger-retaliatory, and
- anger-excitation.
power-assertive
offender purposefully plans the rape, but the murder is an unfortunate aftermath of the violence required to subdue the victim.
POWER-ASSURANCE (2)
- offender also plans the rape but not the murder.
- However, in this case, the murder occurs due to the assailant’s failure and frustration at not being able to successfully seduce the victim.
anger-retaliatory (2)
- plans the rape and murder of the victim.
- The murder is fuelled by anger and the offender selects a symbolic victim on whom to exact his vengeance.
anger-excitation (2)
- offender plans out the rape and murder in order to inflict the greatest amount of suffering on the victim;
- this feeds the offender’s dark fantasies and provides a temporary relief for his desire to control and dominate.
research based on work conducted by
Rossmo (1997), who identified four basic hunting patterns
- Hunter
- poacher
- troller
- Trapper
hunter
Looks for his victims within a geographic space that includes his residence.
poacher
prefers to operate away from his home (e.g., in another city) when committing his crimes.
troller
is an opportunistic offender who comes across his victims while engaging in his daily routines.
trapper
uses his position (e.g., coach, photographer) to lure or set traps (e.g., want ads) to ensnare his victims.
Three different methods of attack were also identified
- raptor
- stalker
- ambusher
raptor
attacks the victim upon encounter.
stalker
follows the victim and waits for the opportunity to attack.
ambusher
only attacks when the victim is within an environment where he is in control (e.g., workplace or home).
Issues with profiling (4)
- Basic assumptions
- Cross-situational consistency
- The Utility of Inferences
- The Dangers of Stereotyping and Discrimination
case linkage
The process of determining whether two or more crimes were committed by the same person
Issues with profiling - basic assumptions (7)
- Some basic assumptions that provide the rationale for criminal profiling have not yet been fully tested or validated.
- When the assumptions have been tested, they have been discredited by data.
- crime scene characteristics do not seem to fit into neatly bound
categories such as “organized” or “disorganized - Instead, they may fall along a continuum, with a few extreme examples being entirely organized or entirely disorganized, but most displaying a combination of types
- concerns about the utility of dichotomous classification of serial killers
- particular crime scene characteristics do not appear to be reliably associated with particular criminal personality types.
- e do not know how the inference process of profilers works or how it should work.
Issues with profiling - Cross-Situational Consistency (3)
- how consistent the behaviour of an individual criminal is across crimes
- there is considerable research indicating that aspects of our basic personalities remain stable over time, our behaviour is also powerfully determined by the situation - Context matters
- the characteristics of the victim (e.g., weak or strong, compliant
or defiant), the setting (e.g., secluded or populated), and the emotional state of the killer (e.g., agitated or calm) can change. If changing situations lead to changes in the crime scenes, then the resulting profiles would change
Issues with profiling - The Utility of Inferences (6)
- Many profiles include speculations that are interesting but of little use to investigators
- researchers found that more than 80% of the statements made by profilers were unsupported-that is, the rationales for the statements were not articulated.
- Further, nearly half of the statements could not be verified even after conviction
- more than a quarter of the statements were ambiguous and open to interpretation
- problems of ambiguity and verifiability
- the number of contradictory elements.
tunnel vision
- focus will be diverted from plausible suspects who do not fit the profile.
- In this way, misleading profiles may enable criminals to evade capture.
Racial profiling
Being viewed as a suspect in a particular crime on the basis of a subset of markers that include race and/or religion is referred to
Issues with profiling - The Dangers of Stereotyping and Discrimination (4)
- In extreme cases, what have been called profiles are little more than biased stereotypes
- Decisions about who becomes a suspect, who should be interrogated, who should be prosecuted, what evidence is relevant, and who should be convicted are sometimes based on the intuitive profiles held by police officers, lawyers, judges, and jurors
- police sometimes rely on intuitive profiles not to solve crimes, but to predict criminal behaviour. Sometimes these predictions are accurate; sometimes they are not.
- tunnel vision - focus will be diverted from plausible suspects who do not fit the profile. In this way, misleading profiles may enable criminals to evade capture.
- racial profiling - people become potential suspects because of easily detected but superficial characteristics like race
Alternative Profiling Methods (3)
- Violent Crime Linkage Analysis System (ViCLAS)
- geographic profiling
- use sophisticated computerized technology to help identify and narrow the pool of potential suspects.
linkage blindness
the inability of law enforcement agencies across different jurisdictions to note that the crimes committed in their respective jurisdictions may in fact be linked
Violent Crime Linkage Analysis System (ViCLAS) (4)
- investigators complete an extensive questionnaire of crime details that were obtained from the investigation
- The information is then input into a database of previously solved and unsolved cases
- Once entered, trained specialists analyze the data to look for clues that may link the cases to each other.
- If a link is found, the relevant investigators are contacted and the lead is pursued
geographic profiling (3)
- a computerized investigative tool that can be used to predict where an unknown offender of a serial crime is likely to reside.
- relies on maps and mathematics
- Computer programs analyze the data to estimate the general vicinity of the criminal’s home or place of work or the potential location of his next crime
anchor point
Computer programs often look for an anchor point from where attacks might be launched
buffer zone
Computer programs often look for an anchor point from where attacks might be launched and some assume a buffer zone around the home of the criminal where he or she is less likely to commit crimes.
distance decay
the probability of an attack decreases as distance from past crime locations increases
behavioural investigative advice (BIA) (4)
- Traditional approaches to profiling attempt to identify the culprit through inference about characteristics based on the crime scene behaviours.
- In contrast, BIA stresses the role of offering advice to investigators on how to use the media, what questions might be asked during police interviews with suspects, and whether a crime might be part of a series of crimes.
- Advisers base their advice on the available research and generally make no claims about their ability to penetrate the mind of the serial criminal.
- Instead of creating a richly detailed psychological portrait of the criminal, the emphasis is on providing useful information to investigators
Probative evidence
provides information that is useful in assessing whether or not a person committed a crime
Probative evidence provides information that is useful in assessing whether or not a person committed a crime. Consequently, two questions are crucial:
- Should information about whether a defendant fits a profile be admissible in court?
(2) Should a defendant’s “fit” with a profile be considered evidence?
