Interrogations-and-Confessions-Handbook

86 A Psychology of Interrogations and Confessions
STATISTICAL PROCEDURES
Factor analysis is a recognized technique widely used in the social sciences that
is often employed as a method of simplifying large and complex sets of data.
It is particularly useful in describing and understanding complex phenomena
such as social interaction. What factor analysis does is to try and make sense
of a large data set by identifying what variables cluster together. To allow for
an effective analysis the procedure dictates that there has to be a sufficient
number of observations. Unfortunately, this requirement could not be fulfilled
in all cases because of the brief duration of some of the interviews (see Table 4.1).
Accordingly, data from cases 1–18 were combined, although there was sufficient
data to analyse cases 19 and 20 independently. In this chapter the findings of
the factor analysis of the combined group (tactics), and cases 19 (Heron) and
20 (Miller), tactics and responses, will be presented.
Utilizing the same statistical programme it was possible to present the factor
scores in graph form. The time segments in each case are featured on the
horizontal axis (x-axis) and the vertical axis ( y-axis) represents the individual
factor score, calibrated by the number of standard deviation (SD) points
from the mean. Descriptive labels were also applied to the factor levels on
the y-axis. Factor scores that did not extend beyond plus or minus one SD,
for example, were referred to as average scores. Factors that extended up to
three SD points were referred to as moderate scores, those extending from
three to five SD scores were labelled marked and finally those that extended beyond
five SD points were identified as extreme scores. These descriptive terms
were arbitrarily applied prior to an examination of any of the cases in this
sample.
The factor analysis employed in the combined group identified six tactic factors.
Factor 1 we have described as an intimidation factor. It is noticeable that
this primary factor contains a very broad range of tactics, and, with eight variables,
it is much larger than the remainder. This factor appears to embody a
standard approach to intimidating a suspect into making a confession. The tactics
concerned are emphasizing the serious nature of the offence, maximizing the
suspect’s anxiety, manipulative use or reference to others, highlighting the experience
of the officers, manipulating self-esteem, manipulating details, multiple
assertions and the use of silence.
The second factor has been labeled robust challenge. This contains the challenges
that the suspect was lying, and one that highlighted inconsistencies. Also
present were the use of interruptions and the continued dispute tactic. Factor
3 has been described as a manipulation factor as it is made up of four purely
manipulative tactics. These were minimizing the serious nature of the offence,
minimizing the suspect’s responsibility, the offer of inducements and suggesting
themes or scenarios.
Factor 4 has been described as questioning style. This was made up of leading
questions, closed questions, echo and multiple questions. Factor 5 is best
described as an appeal factor and contains appealing to the suspect’s good character
or to tell the truth, reassurance, suggestions that it is in the suspect’s
interest to confess and the use of silence. Finally, factor 6 is best described as