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Professor Rachel Zajac Research Interests

 Dr Rachel Zajac

Email rachel.zajac@otago.ac.nz
Tel +64 3 479 3988
Visit Professor Zajac's profile

Eye-Witness Reliability

I work at the intersection of psychology and law. More specifically, I study the factors that influence people’s ability to provide reliable evidence about events they have witnessed. Here are some of the questions that my students and I are currently trying to answer:

What effect does cross-examination have on children’s testimony?

The majority of children testifying in adversarial criminal trials undergo cross-examination, during which their testimony is challenged by the opposing lawyer in an attempt to discredit it. By examining court transcripts and conducting experimental studies of children’s responses to this type of questioning, we have repeatedly shown that most children make changes to their earlier testimony when cross-examined. Furthermore, these changes do not appear to be restricted to corrections of earlier mistakes. In fact, cross-examination-style questioning appears to exert an overall negative effect on children’s accuracy. Our current research is aimed at finding out why this occurs, which children are most at risk, whether we can intervene to facilitate accuracy, and whether adults may also struggle to answer cross-examination questions accurately.

Can an eyewitness’s evidence become contaminated through discussions with another witness to the same crime?

Crimes often involve more than one witness, and eyewitnesses are highly likely to discuss what they saw with each other before investigators arrive on the scene. Unfortunately, incorrect information provided by one eyewitness can contaminate another witness’s evidence. We recently demonstrated that this effect extends well beyond witness’s verbal reports about what they saw, by providing empirical evidence that co-witness misinformation about a perpetrator’s appearance can increase the chances of mistaken identification from a photographic lineup. We are now trying to pinpoint the specific conditions under which this occurs.

How can we help children to avoid making mistaken identifications on photographic lineups?

There are numerous crimes in which a child may hold the only clue to the perpetrator’s identity. Unfortunately, traditional procedures for eliciting eyewitness identification evidence can pose significant difficulty for children. In particular, children appear reluctant to reject photographic lineups, even when the perpetrator is not present. Given the devastating implications of mistaken identification in a legal context, it is crucial that researchers attempt to better understand children’s lineup decisions and, where possible, intervene. We have recently developed the ‘wildcard,’ a simple technique to improve children’s identification accuracy. We are now examining the conditions under which the wildcard is successful, and whether its success may extend to other groups of witnesses who are prone to error (eg, older adult witnesses).

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Publications

Karageorge, A., & Zajac, R. (2011). Exploring the effects of age and delay on children's person identifications: Verbal descriptions, lineup performance, and the influence of wildcards. British Journal of Psychology, 102(2), 161-183. doi: 10.1348/000712610X507902

Jack, F., Martyn, E., & Zajac, R. (2011). The use of visual aids during interviews with child, adolescent and adult witnesses. Proceedings of the 5th International Conference on Memory (ICOM-5). (pp. 137-138). Retrieved from http://www.york.ac.uk/conferences/icom5/Abstract%20Booklet_ICOM5220711.pdf

Jack, F., Leov, J., & Zajac, R. (2011). Adolescents' eyewitness abilities: Addressing a gap in the literature. Proceedings of the 4th International Congress on Psychology and Law and the American Psychology-Law Society Annual Meeting. Retrieved from http://convention3.allacademic.com/one/apls/apls11/index.php?click_key=1&cmd=Multi+Search+Search+Load+Publication&publication_id=483294&PHPSESSID=d460fa471dad9582e4a07c1f65aaec20

Jack, F., & Zajac, R. (2011). Simple versus cumulative misinformation effects. Proceedings of the Society for Applied Research in Memory and Cognition (SARMAC) Conference IX. (pp. 18-19). Retrieved from http://www.sarmac.org/images/upload/downloads/SARMAC_IX_2011.pdf

Jack, F., & Zajac, R. (2011, June). The effect of cross-examination questioning on the accuracy of children's, adolescents', and adults' memory reports. Poster session presented at the Society for Applied Research in Memory and Cognition (SARMAC) Conference IX, New York City, NY.

Chapter in Book - Research

Zajac, R., & Hayne, H. (2009). Cross-examination: Impact on testimony. In A. Jamieson & A. Moenssens (Eds.), Wiley encyclopedia of forensic science. Wiley. doi: 10.1002/9780470061589.fsa471

Zajac, R. (2009). Investigative interviewing in the courtroom: Child witnesses under cross-examination. In R. Bull, T. Valentine & T. Williamson (Eds.), Handbook of psychology of investigative interviewing: Current developments and future directions. (pp. 161-180). Chichester, UK: Wiley-Blackwell. doi: 10.1002/9780470747599.ch10

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Journal - Research Article

Karageorge, A., & Zajac, R. (2011). Exploring the effects of age and delay on children's person identifications: Verbal descriptions, lineup performance, and the influence of wildcards. British Journal of Psychology, 102(2), 161-183. doi: 10.1348/000712610X507902

Zajac, R., & Karageorge, A. (2009). The wildcard: A simple technique for improving children's target-absent lineup performance. Applied Cognitive Psychology, 23(3), 358-368. doi: 10.1002/acp.1511

Zajac, R., Jury, E., & O'Neill, S. (2009). The role of psychosocial factors in young children's responses to cross-examination style questioning. Applied Cognitive Psychology, 23(7), 918-935. doi: 10.1002/acp.1536

Zajac, R., & Cannan, P. (2009). Cross-examination of sexual assault complainants: A developmental comparison. Psychiatry, Psychology & Law, 16(Suppl. 1), S36-S54. doi: 10.1080/13218710802620448

Zajac, R., & Henderson, N. (2009). Don't it make my brown eyes blue: Co-witness misinformation about a target's appearance can impair target-absent line-up performance. Memory, 17(3), 266-278. doi: 10.1080/09658210802623950

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Conference Contribution - Published proceedings: Abstract

Jack, F., Martyn, E., & Zajac, R. (2011). The use of visual aids during interviews with child, adolescent and adult witnesses. Proceedings of the 5th International Conference on Memory (ICOM-5). (pp. 137-138). Retrieved from http://www.york.ac.uk/conferences/icom5/Abstract%20Booklet_ICOM5220711.pdf

Jack, F., Leov, J., & Zajac, R. (2011). Adolescents' eyewitness abilities: Addressing a gap in the literature. Proceedings of the 4th International Congress on Psychology and Law and the American Psychology-Law Society Annual Meeting. Retrieved from http://convention3.allacademic.com/one/apls/apls11/index.php?click_key=1&cmd=Multi+Search+Search+Load+Publication&publication_id=483294&PHPSESSID=d460fa471dad9582e4a07c1f65aaec20

Jack, F., & Zajac, R. (2011). Simple versus cumulative misinformation effects. Proceedings of the Society for Applied Research in Memory and Cognition (SARMAC) Conference IX. (pp. 18-19). Retrieved from http://www.sarmac.org/images/upload/downloads/SARMAC_IX_2011.pdf

Jack, F., Walker, S., & Zajac, R. (2010). Improving children's accuracy on target-absent lineups: Do the physical characteristics of the wildcard influence its success? American Psychology-Law Society Conference (AP-LS). Retrieved from http://convention3.allacademic.com/one/apls/apls10/index.php?

Zajac, R., & Karageorge, A. (2009). Using 'wildcards' to improve the accuracy of children's eyewitness identification: Scope and limitations. Proceedings of the 8th Biennial Meeting of the Society for Applied Research in Memory and Cognition (SARMAC VIII). (pp. 12). Retrieved from http://www.tuat.ac.jp/~sarmac/SARMAC2009Program.pdf

Zajac, R., White, V., & Munn, R. (2007). Acceptance of misinformation from an co-witness: The effect of perceived intoxication. Proceedings of the Association for Psychological Science 19th Annual Convention. Retrieved from http://www.psychologicalscience.org/convention/program_2007/

O'Neill, S., & Zajac, R. (2006). Are you sure? Predictors of children's inconsistency during cross-examination style questioning. Association for Psychological Science 18th Annual Convention. Retrieved from http://www.psychologicalscience.org/convention/program/search/index.cfm?for=yes&type=poster

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Conference Contribution - Poster Presentation (not in published proceedings)

Jack, F., & Zajac, R. (2011, June). The effect of cross-examination questioning on the accuracy of children's, adolescents', and adults' memory reports. Poster session presented at the Society for Applied Research in Memory and Cognition (SARMAC) Conference IX, New York City, NY.

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Conference Contribution - Verbal presentation and other Conference outputs

Osborne, N. K. P., & Zajac, R. (2011, June). An imperfect match: The effect of emotional context on fingerprint matching decisions. Verbal presentation at the Society for Applied Research in Memory and Cognition (SARMAC) Conference IX, New York, USA.

Morten, J., & Zajac, R. (2011, June). Individual differences in adults' performance on photographic lineups: Putting the 'I' in eyewitness. Verbal presentation at the Society for Applied Research in Memory and Cognition (SARMAC) Conference IX, New York, USA.

Morten, J., & Zajac, R. (2010, November). Individual differences in younger and older adults' performance on photographic lineups: Putting the 'I' in eyewitness identification. Verbal presentation at the Psycolloquy Seminar, Dunedin, New Zealand.

Jack, F., Cannan, P., & Zajac, R. (2009, September). Adolescents under cross-examination: A quantitative analysis of lawyers' questions and witnesses' responses. Verbal presentation at the 19th Conference of the European Association of Psychology and Law (EAPL), Sorrento, Italy.

O'Neill, S., & Zajac, R. (2008, November). Factors influencing children's responses to cross-examination questioning. Verbal presentation at the Psycolloquy Seminar, Dunedin, New Zealand.

Zajac, R. (2008, July). The negative effect of cross-examination on children's accuracy: A repeated interviewing effect? Verbal presentation at the 18th Conference of the European Association of Psychology and Law, Maastricht, The Netherlands.

Zajac, R. (2006, November). A simple technique for reducing children's eyewitness identification errors. Verbal presentation at the Psycolloquy Seminar, Dunedin, New Zealand.

Zajac, R. (2006, November-December). Discussions between witnesses. Verbal presentation at the Memory on Trial: The Role of Memory in the Courtroom Symposium, Dunedin, New Zealand.

Zajac, R. (2006, June). A simple method of improving children's accuracy on target absent lineups. Verbal presentation at the 16th Conference of The European Association of Psychology & Law, Liverpool, UK.

Zajac, R., & Henderson, N. (2006, July). The eyes have it: The effect of misinformation from a co-witness on target-absent line-up performance. Verbal presentation at the 4th International Conference on Memory, Sydney, Australia.

More publications...