The Power and Persistence of Contextual Priming: More Risks in Using Police Transcripts to Aid Jurors' Perception of Poor Quality Covert Recordings
| Author | Helen Fraser,Bruce Stevenson |
| Published date | 01 July 2014 |
| Date | 01 July 2014 |
| DOI | http://doi.org/10.1350/ijep.2014.18.3.453 |
| Subject Matter | Article |
THE POWER AND PERSISTENCE OF CONTEXTUAL PRIMING
The power and
persistence of
contextual priming:
more risks in using
police transcripts to aid
jurors’ perception of
poor quality covert
recordings*
By Helen Fraser** and
Independent researcher
Bruce Stevenson***
Senior Lecturer, School of Behavioural Cognitive and Social
Sciences, University of New England, Australia
Abstract A poor quality covert recording from an Australian murder case, along
with the police transcript used in the trial but later shown to be inaccurate, are
used to explore general issues regarding this increasingly common type of
evidence. Two experiments were run, in which participants heard an excerpt
from the audio, first with no transcript, then with suggested and alternative
doi:10.1350/ijep.2014.18.3.453
THE INTERNATIONAL JOURNAL OF EVIDENCE & PROOF (2014) 18 E&P 205–229 205
* Thanks are due to the ‘father’ in this case, and his family, for allowing the audio and transcripts to
be used in these experiments, and also to participantsin both experiments and in a series of pilots.
** Email: helen@helenfraser.com.au.
*** Email: bstevens@une.edu.au.
transcripts. In Experiment 1, they were given no contextual information, while
Experiment 2 started with a background story about the case and the issue the
recording was intended to resolve. Results indicate that background knowledge
of a case can dramatically increase listeners’ acceptance of a police transcript,
even when the transcript is manifestly inaccurate. It is suggested that such
contextual priming may affect not just juries but others involved with the trial,
and recommended that police transcripts be treated with more caution than is
currently common with Australia’s ‘ad hoc expert’ rules.
Keywords Forensic transcription; Forensic phonetics; Priming; Cognitive bias;
Digital evidence; Indistinct audio
overt recordings are used as evidence in increasing numbers of criminal
cases, often providing useful information not available by other means.
One problem is that, due to the manner in which they are obtained, their
quality is often very poor—to the extent that, without prior knowledge of the
contents, few if any words can be clearly identified.
For this reason, it is common, in Australian and other jurisdictions, for covert
recordings to be transcribed by those with relevant background knowledge,
typically (but not only) by detectives investigating the case. Of course, transcribing
poor quality audio, even for someone with background knowledge, requires
repeated listening. In Australian and other jurisdictions, the law grants the status
of so-called ‘ad hoc expert’ to those who have listened many times to a recording.
This status allows detectives to provide their transcripts in court, as an aid to the
jury’s perception of the audio.1
Unfortunately, police transcripts are frequently inaccurate, incomplete or
otherwise misleading.2To prevent potentially adverse effects on jurors’ interpre-
tation of the audio, judges in cases involving police transcripts are required to
caution the jury to use the transcript only as an aid, relying on their own ears to
decide what is actually said in the recording.3
Is this a sufficient safeguard? Phonetic science would suggest not.4Well-estab-
lished evidence demonstrates that seeing an inaccurate transcript can influence
206 THE INTERNATIONAL JOURNAL OF EVIDENCE & PROOF
THE POWER AND PERSISTENCE OF CONTEXTUAL PRIMING
C
1 See, e.g., Evidence Act 1995 (NSW), s. 79(1).
2 M. Coulthard, ‘Some Forensic Applications of Descriptive Linguistics’ (2005) 9 VEREDAS—Revista de
Estudios Linguísticos 9; P. French and P. Harrison, ‘Investigative and Evidential Applications of
Forensic Speech Science’ in A. Heaton-Armstrong, E. Shepherd, G. Gudjonsson and D. Wolchover
(eds.), Witness Testimony: Psychological, Investigative and Evidential Perspectives (Oxford University Press:
Oxford, 2006) 247; R. Shuy, Language Crimes: The Use and Abuse of Language Evidence in the Courtroom
(Blackwell: Oxford, 1993).
3 See, e.g., J. Wood, Report 136: Jury Directions (NSW Law Reform Commission: Sydney, 2012) sections
6.52–6.56.
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