Enhancing the Effectiveness of Video. Identification

Transcription

1 Enhancing the Effectiveness of Video Steve Darling Identification Amina Memon Tim Valentine Research funded by:

2 Line ups and Identification What are they for Parades Prosecution must satisfy the court that the person that evidence from an eyewitness is reliable. Line-ups offer a means of establishing eyewitness identification by a witness of a culprit. Unfamiliar faces / Familiar Faces. Biggest benefit in cases where the suspect is unknown to the witness

3 Line-up Procedure in the UK Traditional Live Line-ups Video Line-ups Police and Criminal Evidence Act (1984) Revisions Video lineups now preferred to live (Code D para 3.14) Video lineups should use moving images (Code D para 3.14) Exceptions: Non Cooperation Replication of marks VIPER PROMAT

4 Current Nuffield Foundation Funded Project Evaluation of theoretical issues discussed in scientific literature in an ecologically valid, UK based procedural context VIPER Key Issues: Strict line-up rules Foil Selection Image type

5 Assessment of Line-up Procedures In experiments we can control CULPRIT PRESENCE. Taking account of all possible outcomes Culprit Present (CP): Correct ID,, Incorrect Rejection, Incorrect ID of a known foil. Culprit Absent (CA): Correct Rejection: Incorrect ID of a known foil, incorrect ID of a suspect. PICKOUTS and failed ID

6 Design of Research 4 Large scale experimental studies Each of around 200 participants each 2 Part experiments Presentation (Simulated Crime) Delay (2 20 days usually 7-10) Line-up Administered (CP/CA) Innocent Suspects Issues looked at independently in this talk Each comparison minimum group size = 100 POWERFUL DESIGNS MANY PARTICIPANTS

7 Experimental Scenario Simulated crime committed by an actor

8 Simulated Crime Health and Mood Study

9 Simulated Crime

10 Simulated Crime Oh didn t see you there; I m just taking this to the medical department

11 Simulated Crime What are you doing? Nothing Doesn t look like nothing. Is that your laptop. No You were trying to steal it, weren t you?

12 Simulated Crime No. Did you see me do anything?

13 Simulated Crime Did you see me do anything?

14 Simulated Crime Did you see me do anything?

15 Simulated Crime OK, but go away!

16 Experimental Scenario Simulated crime committed by an actor Witnesses give description/ Several days later Witnesses try and identify culprit from the line- up

17 Issue 1: Line-up Rules Terminology North American Strict Rules / Instructions Sequential UK PACE - Standard VIPER / PROMAT Simultaneous

18 Issue 1: Rules Theoretical background: Strict Rules Relative judgements Photo spreads Reduction in False ID no expense to true ID Steblay et al (2001): Memon & Gabbert (2003) reduced rate of choosing Used in some North American jurisdictions Is there a benefit of using strict rules with VIPER

19 Culprit Present Strict vs Existing rules (p <.01) PACE STRICT % of total ppts per condition CORRECT ID INCORRECT REJECTION Outcome ID FOIL

20 Culprit Absent Strict vs Existing rules (p <.1) PACE STRICT % of total ppts per condition CORRECT REJECTION ID FOIL Outcome ID SUSPECT

21 Strict Rules - Conclusions Lowered correct IDs on CP line-ups No reliable differences in CA line-ups Choosing lowered overall Strict presentation within VIPER: A way of making line-up performance worse. No case for adopting strict presentation in the UK. Comparison doesn t t necessarily contradict evidence acquired using photo spreads

22 Issue 2: Foil Selection Picking foils in line-ups PACE rule: The set of images must include the suspect and at least eight other people who, so far as possible, resemble the suspect in age, general appearance and position in life. (Code D, Annex A, Para 2)

23 Suspect Resemblance and Culprit Description Suspect Resemblance (SR) Pick on basis of appearance Lineup of Clones Culprit description (CD) Pick on basis of description match Propitious Heterogeneity

24 Operational Implications Problems with culprit description Difficult situations Inaccurate or incomplete descriptions good descriptions changed appearance

25 Culprit Present SR vs CD (n.s.) SR CD % of total ppts per condition CORRECT ID INCORRECT REJECTION Outcome ID FOIL

26 Culprit Absent SR vs CD (n.s.) SR CD % of total ppts per condition CORRECT REJECTION ID FOIL Outcome ID SUSPECT

27 Checking the Materials: High Similarity 7 6 Independent ratings Good Match 7 Foil witness description match (p <.05) SR CD SR CD Foil Suspect Similarity (p <.05) 1

28 Foil Selection - Conclusions There was no evidence of differences between SR and CD foil selection Ratings This was not because of problems with the materials Recent data from Clark and Tunnicliff (2000) No evidence to support CD introduction in UK Case against CD strengthened by difficult situations

29 Issue 3: Image Movement Some evidence suggests that there may be a benefit of using moving image (and live) line-ups rather than static image photo spreads Aim to see if such a benefit occurs in VIPER line- ups Operational issues: Still images and replication Cost implications of moving images

30 Culprit Present Moving vs Still (n.s.) Moving Still % of total ppts per condition CORRECT ID INCORRECT REJECTION Outcome ID FOIL

31 Culprit Absent Moving vs Still (p <.05.) Moving Still % of total ppts per condition CORRECT REJECTION ID FOIL Outcome ID SUSPECT

32 Experimental Data Fewer incorrect ID foils in CA line-ups. Suggests that moving images are better BUT: very small effect, might not generalise to innocent suspects. Attempt to replicate effect

33 Culprit Present Moving vs Still (n.s.) Moving Still % of total ppts per condition CORRECT ID INCORRECT REJECTION Outcome ID FOIL

34 Culprit Absent Moving vs Still (ns) Moving Still % of total ppts per condition CORRECT REJECTION ID FOIL Outcome ID SUSPECT

35 Movement - Conclusions Failed replication If any, only a small, elusive effect No grounds to reject the use of still line- ups where it would be useful Still line-ups often used for non-standard line-ups, replications etc. PACE is right to prefer video wherever possible. Only applies to VIPER stills

36 Innocent Suspect Identifications Throughout the current experiments: Around 2 % of witnesses viewing a culprit absent line- up picked out an innocent suspect Around 23 % of witnesses erroneously selected a foil an extrapolated risk of misidentification of an innocent suspect of around 3 % It is hard to see how this might be improved in practice. A low level of misidentification BUT it is NOT ZERO.

37 Innocent Suspect Identifications More line-ups = More misidentifications If line-ups are done per year, and 10 % contain an innocent suspect. = innocent suspect misidentifications from lineups per year. Risk increases if poor witnesses are included Recommendation: Only run line-ups where necessary for a case Avoid Might as well line-ups from weak witnesses.

38 General Summary UK rules better than US strict rules for VIPER / PROMAT tyoe lineups SR lineup selection better than CD Moving images possibly slightly better than stills. We can make PACE line-up procedures worse, but using the theoretical approaches described, we have not been able to improve them. These were well designed, powerful experimental studies as good / better than the theoretical studies upon which the they were based.

39 Implications for policy Current PACE guidelines and VIPER/PROMAT parades offer best practice at present, and will not be improved by adding strict rules, or description based foil selection strategies. Current practice of using moving images where possible is best practice, although use of stills is acceptable if it is useful.