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EYEWITNESS IDENTIFICATIONS

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          EYEWITNESS
     IDENTIFICATIONS


Why Study This?
There are 80,000 cases each year in the US
where the only critical evidence against a
  person is an eyewitness identification.




 It is a fact that eyewitness identifications
  are made under situations of incredible
duress – they can be more or less accurate.
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         STAGES IN THE
IDENTIFICATION PROCEDURE


1. Verbal Description


2. Police Sketch/Composite Image


3. Mugshot Identification


4. Lineup/ Identification Parade




        Value versus pitfall
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                Step 1:
     VERBAL DESCRIPTION


   - determines direction of investigation


BUT: A host of factors can influence
its accuracy:
   - delay between event and description
   - reconstructive
   - bias from expectations/stereotypes
     (MacLin, Malpass & Herrera, 2000)
   - limited by language –verbal
     overshadowing


    Description will undoubtedly lose
  something and may even insert things.
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                   Step 2:
          POLICE SKETCH


   - guides further investigations
   - acts as a visual prompt for the public
   - visual cue to refine the verbal
     description


BUT: Errors can be introduced
   - subtle discriminations required
   - bias of operator/artist
   - reinforcement of initial errors


     The sketch may bear a striking
 resemblance to a person with two eyes,
      two ears, a nose and a mouth.
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                 Step 3:
 MUGSHOT IDENTIFICATION



   - recognition is easier than recall
   - visual over verbal method of ID


BUT:
   - mugshots may not be current
   - viewing conditions may interfere
   - source monitoring errors –bystander
     effect
   - social pressure to choose

High likelihood of mistaken identification
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                   Step 4:
           POLICE LINEUP


Based on sound principles:
   - correct identification of the suspect-
     strengthens prosecution


   - identification of non-suspect –
     eliminates the suspect, examine the
     alternative, question validity of witness


   - No identification –
     eliminate the suspect/memory too weak or
     witness shows a conservative bias against
     making a mistake.


    Good test of police hypothesis and
             witness credibility
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        POLICE LINEUP – A
  PROBLEMATIC PROCEDURE


   - Social Pressure to choose
   - Source monitoring error –
     recognising from scene/mugshots
   - Suspect stands out
     (Lindsay & Wells, 1980)
   - Functional size of lineup is small
     (Malpass & Lindsay, 1999)
   - Relative vs Absolute strategy


Recommendations:
UK - The Devlin Report (1976)
US – American Psychology and Law
Society (APLS) Wells et al. (1998).
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              REVISIONS TO
IDENTIFICATION PROCEDURES

1. Non-biased instructions
   Malpass & Devine, 1981, Steblay, 1997


2. Blind procedure –confidence malleability
   Luus & Wells, 1994


3. Remove mugshot stage
   Devlin, 1976


4. Fair lineup – suspect does not stand out,
   fillers fit witness description
   Luus & Wells, 1991


5. Sequential over simultaneous lineup
   Lindsay & Wells, 1985
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               SUMMARY


Eyewitness accuracy can be boosted by:


   - Careful use of verbal descriptions
   - No/limited use of mugshots
   - Revised procedures for lineups
       Blind
       Fair
       Non-biased instructions
       Sequential presentation


               Simultaneous      Sequential
                 correct          correct
  T.present       61%              50%
  T.absent        39%              78%
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Lingjuan Ma Lingjuan Ma MS
About work for China Compulsory Certification. Some of the documents come from Internet, if you hold the copyright please contact me by huangcaijin@sohu.com