Witnesses' failure to detect covert manipulations in their written statements

Anna Sagana*, Melanie Sauerland, Harald Merckelbach

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

81 Downloads (Pure)

Abstract

Law enforcement agencies and legal professionals often have to rely on witness statements. Undetected errors in witnesses' statements, however, could impede the accurate reconstruction of a crime and lead to the incrimination of innocent suspects. Here, we examined whether witnesses can detect manipulations in their written statements. We expect that writing a statement could provide a good means for discrimination between what is truly recalled and what is an error. This is because writing allows to monitor and control the previously produced information. In 3 experiments, participants watched a mock crime film and subsequently provided a written statement of what they had witnessed. Following a delay of several minutes (Experiment 1), 48hr (Experiment 2), or 1month (Experiment 3), participants were exposed to and interviewed about their testimony. Unknown to them, they were confronted with statements, which included 4 secretly manipulated details. Participants' missed a substantial number of manipulations in their written statements. Importantly, the detection rates varied as a function of delay (Experiments 1 and 2: 74-89%; Experiment 3: 36%-52%). Detection rates also varied as a function of the type of details that were manipulated. Our findings indicate that writing a statement comes with limited benefits in witnesses' ability to detect errors in their statements.

Original languageEnglish
Pages (from-to)320–331
Number of pages12
JournalJournal of Investigative Psychology and Offender Profiling
Volume14
Issue number3
Early online date2017
DOIs
Publication statusPublished - Oct 2017

Keywords

  • BLINDNESS
  • EFFICACY
  • EVENTS
  • EYEWITNESS TESTIMONY
  • FACIAL RECOGNITION DECISIONS
  • FALSE MEMORY
  • IMPAIRMENT
  • MEMORY SUGGESTIBILITY
  • MISINFORMATION
  • PRESENTATION MODALITY
  • choice blindness
  • interrogation protocol
  • misinformation
  • source monitoring
  • witness statements

Cite this