Latent print examiners often find themselves in situations
where fatigue may affect their performance. The Expert Working
Group on Human Factors [5] identified fatigue along with stress,
complacency, overconfidence, and task overload as examples of
adverse mental states of an examiner. In addition to these mental
state changes, physical changes can occur such as eyestrain and
back pain from looking through a loupe at latent print impressions.
The Working Group report specifically identified several factors
that could contribute to fatigue, including being on call for crime
scene investigation, working through backlogs, and long hours as
practices that could reduce performance. However, the literature
contains relatively little direct evidence of the effects of fatigue on
latent print examination.
To measure the effects of fatigue in tasks that resemble actual
casework, we tested examiners both before and after a visual
matching task that was designed to induce fatigue. We recorded
both behavioral accuracy as well as eye gaze, which will allow