Journal of Forensics Sciences
Reprinted with author permissions:
Charlton1, Peter A.F. Fraser-Mackenzie1, and Itiel E. Dror2
of Psychology; Faculty of
Medicine, Health and Life Sciences;
of Southampton; Southampton, United Kingdom.
2 Cognitive Consultants International Ltd.
In this study
we investigated the emotional and motivational factors involved in
fingerprint analysis in day-to-day routine case work and in
significant and harrowing criminal investigations. Thematic analysis
was performed on interviews with thirteen experienced fingerprint
examiners from a variety of law enforcement agencies. The data
revealed factors relating to job satisfaction and the use of skill.
Individual satisfaction related to catching criminals was observed,
this was most notable in solving high profile, serious, or long
running cases. There were positive emotional effects associated with
matching fingerprints and apparent fear of making errors. Finally,
we found evidence for a need of cognitive closure in fingerprint
examiner decision making.
forensic science, expertise, motivation, emotion, satisfaction,
qualitative, thematic analysis, need for closure
analysis has been a cornerstone of forensic investigation for well
over 100 years. Such is the trust in fingerprint evidence that it is
rarely questioned by the public and judicial system. Indeed, in the
vast majority of cases latent print examiners’ findings and
conclusions are unchallenged and accepted at face value. Many people
arrested and charged as a result of fingerprint evidence will often
admit to crimes based solely on the knowledge a fingerprint match
has been confirmed. Many arrestees feel under intense pressure to
confess (1), so the presence of forensic intelligence only serves to
intensify that pressure. The validity of fingerprint science and the
trust placed in the evidence is based on the biological uniqueness
of friction ridge skin and the methodology of fingerprint
identification that is considered to produce correct matching with
zero error rates (2). Yet latent print examination, considered
unquestionable and scientific, is now coming under increasing
scrutiny in the courts (2). Errors in the analysis of fingerprint
evidence in high profile cases around the world (3, 4) have resulted
in legal council, media and public attention focusing on the core
issue of what is to be considered one of the most reliable and valid
forensic science (5).
case is one of the most notorious of all the recent controversies in
latent print examination. Shirley McKie was arrested for perjury for
stating under oath during a murder trial that a thumb print which
was matched to her was not hers (4). McKie was only vindicated after
latent print examiners from other agencies around the world
challenged the validity of the identification. In contrast to the
Mayfield case where the error has been acknowledged, to this day
there are experts in latent fingerprint analysis who still disagree
whether it is hers or not. This inability to reach an agreed
conclusion raises a number of issues such as, “can anyone actually
be certain that Shirley McKie didn’t make the print in question
given the need for, and lack of any consensus over the conclusions
reached by opposing opinions of latent print examiners"? (2) The
erroneous fingerprint identification by FBI latent print examiners
of Brandon Mayfield as part of the forensic investigation of the
2004 Madrid Bombings was another highly contentious case (6).
Mayfield’s fingerprints were alleged to have been identified against
those found on a bag of detonators found in Spain after the bombings took place.
However, due to subsequent re-analysis carried out after the Spanish
authorities questioning the accuracy of the identification, the FBI
fingerprint experts conceded they had been incorrect in their
original analysis. These cases, as well as other errors and
controversies, have resulted in fingerprint analysis coming under
attack from both the judiciary and academia. Some (2, 5) have
questioned the very underlying scientific assumptions made by
fingerprint experts. Fingerprint examination has now been a topic of
scientific inquiry in academia, the criminal justice system and the
forensic science community (7, 8, 9, 10). The US National Academia
of Science has created an independent forensic science committee to
assess the present and future needs of forensic science (11).
Comparing two fingerprints involves examining a specific target area
of friction ridge detail on one print and searching for a matching
correlation of friction ridge detail on another print. Once enough
characteristics have been matched by the examiner then they may
conclude the pair of prints is a match (12, 13).
identification involves visual search and processing of visual
information. Scientific studies show that the interpretation and
selection of visual information can be greatly affected by emotional
state. Examples of this are that biases of cognition result in
preferential processing of visually threatening stimuli (14),
processing of facial expressions corresponds to the emotional state
of the perceiver (15), and even ambiguous sounds can be processed
and interpreted in a way that correlates to the person’s emotional
state (16). Such top-down processing effects enable context and
background knowledge to influence the selection and processing of
information (12, 14). For details see past research examining the
relationship between emotions and fingerprint analysis which showed
that contextual information like emotional background stories of
crimes and explicitly disturbing photographs from crime scenes may
affect how fingerprints are matched. This research demonstrated that
the decisions and conclusions may differ dependent upon the context
in which the evidence was presented. The results indicated that
participants were more likely to match different but ambiguous pairs
of fingerprints in the highly emotional condition (15). Further
studies examined whether fingerprint examiners could objectively
focus solely on feature information in fingerprints without being
misled by extraneous information such as context (8). Fingerprints
were used that had previously been examined and assessed by latent
print examiners to make positive identifications against suspects.
Then the same examiners were presented with the same fingerprints
again, but this time given a context that strongly suggested that
they were a no-match, and hence the suspects could not be
identified. Within this new context, most of the fingerprint experts
made different judgements, thus contradicting their own previous
identification decisions (9). Additional research demonstrated that
fingerprint experts were vulnerable to biasing information even when
they were presented with relatively subtle and routine day-to-day
contexts, such as corroborative (or conflicting) evidence of
confession to the crime. The results were similar to the earlier
experiments; it was found that context influenced the judgement of
the experts. Thus, it appears that contextual information does not
need to be extreme and unique to influence experts in their
fingerprint examination and judgement (10).
information is only one of many cognitive influences that may affect
fingerprint expert performance. Other influences may be need for
cognitive closure, emotional rewards, belief perseverance,
escalation of commitment, conformity, motivated perception,
self-fulfilling prophecies, cognitive dissonance, wishful thinking,
diffused responsibility, framing, and a whole set of established
cognitive and psychological phenomena (17, 18). In this paper we
focus on investigating two such influences: need for cognitive
closure (simplistically stated, it is the psychological need to
bring a decision making process to a definitive conclusion and
termination so as to avoid ambiguity or unresolved issues), and
emotional experiences (simplistically stated, the feelings (or
expected feelings) associated with fingerprint analysis, including
reward when one finds a match as well as fears associated with the
possibility of making an error). Kruglanski et al. (19, 20) find
that participants motivated to avoid closure generate the largest
number of hypotheses, in contrast to those motivated for a need for
closure who produced the fewest hypotheses. As the need for closure
is higher, quicker judgements are attained with higher confidence
associated with those decisions. High need for closure leads to the
“unfounded confidence paradox".
This paradox arises when there is reduced information processing but
at the same time higher confidence in those judgements and
conclusions. Thus, a need for cognitive closure may lead to lower
decision thresholds, but increased confidence. However, Ask et al.
(21) found only partial support to the hypothesis that investigators
with a high need for closure are less likely to acknowledge
observations that are inconsistent with their belief of guilt. It is
therefore important to investigate if the need for closure plays a
role in fingerprint analysis.
The need for
closure also enhance a desire for consensus (20), thus adopting the
“path of least resistance" to achieving agreement with others. This
may entail, for example, derogating those who hinder consensus and
complementing those who facilitate it (20). This is important and
relevant to the area of fingerprint because the need for closure
does not only potentially affect the initial analysis, but may be
critical to the verification stage at ACE-V (12) as well as
arbitration. Given that fingerprint examiners" decision making can
be affected by extraneous influences such as emotional response,
context and motivations, then the apparent presence of emotions or
motivations in fingerprint examination will be indicative that these
influence play a role in fingerprint analysis. Conversely, if
emotions and motivations were absent from day to day experiential
work of fingerprint examiners then that would support that they are
not affected by them. As yet there has been no investigation into
the emotional experiences of operational fingerprint examiners. This
study is a step in examining these issues and it is hoped it will
yield valuable insights into the potential role of emotions and
motivations on decision making. The qualitative study reported here
enabled an examination of the views of fingerprint examiners without
the restraint of preconceived theory or experimental restrictions.
The aim of this study was to highlight and understand the work of
fingerprint experts from a new perspective.
qualitative studies have been used in other domains, to the best
knowledge of the authors, there has never been a qualitative study
investigating the emotional and motivational experience within the
fingerprint domain. There are a number of important issues
associated with this research. Prior to this study, it was only
possible to speculate about the emotional experiences of fingerprint
examiners. The top-down contextual and motivational (and many other
cognitive mechanisms) effects often occur without consciousness
(22). As a result, we cannot expect participants to be aware of any
information processing effects. Therefore we undertook individual
interviews in an attempt to obtain a broad range of views and then
perform thematic analysis on the findings in an attempt to uncover
trends in the responses of the participants. Thus determining themes
and underlying similarities in the experience of the decision
makers. Similar research methods were evident in Hermsen and Have’s
(23) study in which semi-structured individual interviews were
conducted. They attempted to determine the specific moral and
emotional considerations and arguments that might arise from people
who must decide whether or not to withhold treatment in a palliative
care scenario. They similarly studied a relatively small participant
base and as such looked across various care giving environments to
get broad, underlying characteristics. The aim of our study is to
find broad themes that occur across the whole sample and not
differences between participants. By observing themes that were
discussed by each and every participant so we could derive themes
that can be generalized to the larger forensic community.
The aim of
this study was to qualitatively investigate themes about emotional
and motivational factors that relate to the latent fingerprint
participants were interviewed from a variety of law enforcement
agencies who were all latent fingerprint examiners, each with at
least 7 years experience. The participants included those involved
in the investigation of daily volume crime such as burglary and
vehicle theft, others who dealt with the more rare investigations of
rape, murder or armed robbery, as well as senior officers and
managers with a number of years experience. The broad range of the
participants’ experiences decreased the chance of deriving
participant or role specific themes. All participants were fully
trained latent print examiners, and performed fingerprint comparison
analysis daily. Each interview lasted approximately 30 minutes.
semi-structured interview technique was employed, which involved the
use of an interview guide (see appendix 1). This method was used in
preference to a fully structured interview as heavily structured
interviews tend to constrain participants’ responses towards the
researchers preconceived ideas. Rather the more open-ended structure
allowed participants to respond in a naturally ambiguous way. It has
been suggested that when participants are offered multiple options
they tend to constrain their responses between options and as a
result we can miss some important areas of internal conflict (24).
Furthermore, structured questions can impose ideas and we may lose
vital areas of interest that would otherwise be missed, for example
how people make sense of their experience. The interview questions
encouraged participants to talk about the various different aspects
of their work from the mundane to the more serious and disturbing
casework where potentially emotional feelings are engendered, and to
attempt to probe any expression of affect that arose. All
participants were asked to talk about three aspects of their work:
1. Day to day fingerprint analysis processes. 2. Particularly
harrowing or difficult cases. 3. What it meant to them as
individuals to be involved in latent print identification.
interviews, more direct and probing questions were asked in order to
gain further information and resolve any potential
misinterpretations by the interviewer. Probing also facilitated the
interviewee’s own understanding of the framework of meaning without
imposing the researcher’s assumptions (25). It was also important
that the questions were not so non-directive that they actually led
to more constraint on the participants, as they may spend more time
and energy guessing what the interviewer wanted to know (26). We
attempted to find a balance between non-directive general questions
that might elicit emotional responses and more direct prompts to
examine discussion points in more detail.
interviews were conducted at various operational fingerprint
laboratories away from the noise and distraction of the operational
environment. Before the interviews, participants were given
information and consent forms, and were informed of the general
nature of the study. All participants were guaranteed anonymity. All
the interviews were recorded so the interviewer could be sure that
all information was captured. The interviews were subsequently
transcribed verbatim, using; “…" to signify pauses, “CAPITALS!" to
signify exclamations, “[xxxx]" to signify named or identifiable
persons, and “[text within brackets]" for clarification. Also, notes
were taken during the interview about how the interviewee appeared,
how the interview was progressing, and other appropriate events
during the interview.
thematic analysis protocol, codes were assigned to various segments
of the text (see appendix 2). It was not clear what the findings
would be and there was little in the way of guidance from past
research. As a result, specifics were inductively coded, whereby
individual categories were generated from the interview text itself
rather than from specific theory (27). Initially, the coding was
very broad to encompass anything which had emotional content. Then,
as subsequent themes appeared these were broken down into separate
codes; for example, distinguishing positive emotions from negative
ones. It was important to be cautious not to generate too many
categories. Consequently, a few, broad, general themes were chosen
as this allowed much greater generalization. It was also important
to this particular study that both latent and manifest content was
coded. Although this involves a certain amount of interpretation by
the researcher, it was hoped that any clarifications made during the
interview and the concurrent notes made would avoid inaccurate
is vital in any qualitative study. It was important that the coding
was both stable and consistent and that it had good reproducibility
(28). There is another reliability measure, accuracy, which refers
to the extent that the coding corresponds to a previously generated
standard or norm, which provides the strongest form of reliability
(29). However, as this is a new area of study there are no standards
to compare it against. As a result it was not possible to measure
accuracy reliability. However, it is hoped that the themes from this
study might be used to gauge further qualitative studies
investigating the emotional or motivational experiences of forensic
or criminal investigative personnel. Inter-rater reliability was
tested by two independent analyses. Only agreements above .65 were
considered (30). If sufficient reliability was not apparent, further
refinements to the coding were performed in order to increase
reliability. To ensure the stability of the initial codes, they were
rated twice on two separate occasions. This ensured test-retest
reliability and inter-rater reliability. After assessment of the
percentage level of agreement between the raters, it was found that
there was an overall coding agreement between raters of .74.
Allowing for chance coding agreements a further statistical analysis
was performed. An overall free marginal (where raters are not forced
to assign a certain number of cases to each themed category) Cohen’s
Kappa of .69 was achieved (31, 32). It was decided that this met the
level of reliability required to ensure the themes highlighted in
this paper were representative and reliable.
revealed five main themes associated with emotion and fingerprint
analysis: Reward, motivation, satisfaction, fear and need for
closure. These themes were broken down into separately coded
categories; job satisfaction and pride associated with the use of
skill; motivation, satisfaction and hope, associated with catching
criminals and solving crime; the expression of satisfaction and
motivation associated with working on more serious or long running
cases; the feelings directly associated with searching for and
finding matches; expressions indicating a need for closure on
casework and emotional feelings associated with making mistakes. As
a precursor to the discussions held with the fingerprint examiners,
each participant was given an opportunity to explain the
identification process of fingerprint analysis and to go into some
detail regarding the methodology of comparing fingerprints. It was
considered important that this be reported within this study. As
will be highlighted later, there was objectivity in their
methodological description (see examples below) which was in stark
contrast to the emotive language and motivations observed later.
“…you will run through a series of questions in your mind; quality
over quantity, clarity within the mark, the tolerance that you will
give to it, what volume of detail have you got? Can you see ridge
flow, can you see ridge pattern, what features are there within
there, i.e. are there any ridge characteristics? Can you see a scar?
Can you break it down even further because in relations to the
clarity can you see a particular shape or ridges or pores within
there? Anything else which is detail which is going to be useful you
to enable you to make a comparison.” “ …assess the value of the
marks…we got three basic categories…no value…which means there is so
little information in the mark you can never individualise it…then
you move on to a mark that is suitable for a direct comparison.”
“…have a look at that mark to see what available
information is on that mark….to see if there is any idea of which
finger that mark came from…any other indications…left hand…right
hand…. Then I would look at the fingerprint form then if I don’t
know which finger straight away to compare it to…If there was no
clear indication, I would compare all ten fingers and analyse the
mark from the mark to the fingerprint form looking for anything that
looks similar…any points or characteristics that show in both
impressions…I build up in my mind what characteristics are similar
and I will keep going until I have identified…or not identified.”
Satisfaction Related to Skills
There was a
great deal of pride and “job satisfaction" exhibited by the
fingerprint examiners interviewed associated with the process of
fingerprint analysis and the science associated with friction ridge
skin. There was a sense of pride in the skills they had learned and
a real sense of civic duty and making a difference to society.
“…from a personal perspective I thoroughly enjoy it [the job]
because it involves patience, it involves tenacity, and it involves
you really having to concentrate and focus, and the reward comes at
the end of the day when you can actually walk away saying “I"ve
done absolutely everything I can". ” “…using your skill and
expertise gives you that bit of drive and feeling, “yeah I"ve done
something no one else can do", and makes you feel worthwhile and
feel, you know, you can’t be replaced [laugh].” “…the thing I still
like about this job is the idea that when I get home and I have had
a frustrating day and things aren’t going right… you at least know
that all my efforts are going to have a tiny but important part of
improving society… improving life generally for people a little
bit…” “…you are doing something useful and you have developed a
skill or a talent that is being used and that gives you a sense of
satisfaction…” “…you are believed in…you are in a position of
importance…it’s a nice feeling…” “…I am proud of my position in
it…proud of what I have achieved.” “I am very proud of the service
that we do for the public.” The increase in
computer technology in fingerprint analysis has resulted in some
fingerprint examiners feeling under valued as specialists, which
could be seen an obvious drain on morale. Intriguingly however,
there was not a sound consensus on the true value of technology in
the domain. Indeed, some of the comments from examiners were
contradictory in nature, some feeling technology de-skilled them,
whilst others got heightened feelings of pleasure from using
technology to search for cold cases. “…which is a shame because
we use computer technology more and more and more so it removes the
ability of fingerprint officers to use their brain and actually use
has always given more satisfaction…One to one suspects doesn’t give
you the same buzz I suppose as a search on ident 1.”
Satisfaction with Crime Solving
sub-category of satisfaction demonstrates how the clinical and
scientific job of matching details and patterns within fingerprints
has a very human element associated with a personal interest in
solving crime and catching criminals. “…I think there will
generally be a … very…a lot of …pleasure about it if the case is
resolved to a successful conclusion, with a successful conviction, I
think that would be a natural thing. If the case remains open then
there will always be work to be done. There is always a potential of
finding someone.” “I mean, I was beginning to give up hope of ever
matching this fingerprint, I thought, “oh they’ll
get it in DNA" they’ll, they’ll, they’ll, find someone and say,
“there we go, that, that’s the…the perpetrator", and it won’t even
match this fingerprint and all my time would be wasted.” “We catch
more in here than the Police officers do on the street and the
Police officers are praised and get more money and things [laugh]”
“…they don’t realise the work that’s gone on behind the scenes and
its nice, it, it is really satisfying, it sounds really sad, but
catching people. You don’t really see the name or the person you
just see that fact that you’re hopefully solving a crime.”
“….the whole case was identified to people they wanted it
identified to…it was a good result…. That sticks in my mind because
I got good feedback from the police officer and the OIC.”
comments demonstrate that matching fingerprints is not just a
laborious task of visual search and comparison of details. It
appears that analysts feel a direct link between finding matches and
actually solving crime. This has significant importance because it
suggests that the frame of mind of the examiner is variable in
different cases being processed depending on the importance of
catching the perpetrator.
Satisfaction Associated with Case Importance
specific comments concerning the experience of reward linked to
working on more serious, or longer running cases. “…for me
personally working a long protracted case it is rewarding because
you know you are working towards an end goal.” “…that [the feeling]
was, that was great, I mean, to be involved in such a high profile
case and finally get a match.” “…well it depends on the type of work
that you do. Print to print analysis, just so many of those going on
it [feelings of satisfaction] doesn’t really happen. But again it
depends on the severity of the crime. If you’re
getting volume crime like car theft, or shop lifting, or whatever,
and then you get identifications on that, then it’s okay. If you
haven’t" had any in a while in a week or for a month, then its
really good.[…] If it’s a more serious offence then I makes you feel
even better, er, even more, um, happy with your job,…” “…the scale
of the crime that they were doing was very significant and to
actually be a part of that was great, it was really nice, all the
benefits are you’re actually catching some one up, quite high up the
food chain so, it is , really, a really nice feeling.”
some interesting counters to these statements where the severity of
the case was said to be irrelevant and that both volume crime, and
the more serious crimes like murder, were treated the same way.
“The fact of the matter is, it doesn’t matter what the offence is.
What we are focusing on are the crime scene marks and the end
result, again, is to complete your analysis, your comparison, and
verification to the best of your ability, using your skill.” “It
doesn’t matter, really, the size of the case, you know.” In
contrast, participants also made comment that: “That’s not to say
that the same commitment doesn’t go with each job but, you, you
know, everyone will do more work for a murder than they would for a
shop lifting” “…you know, especially with a serious case you are
liable to get a lot more suspects and you are still going to have to
look at that piece even if you have a strong feeling that it belongs
to somebody else other than the person you are looking at…You still
have to look just in case because no one wants to be in the position
of ignoring something. “Major crime sounds glamorous but you don’t
actually get out there and see much of the major crime…it’s
just a pile of work and I actually enjoy the small cases better…the
day to day volume crime I actually enjoy better.” “…these big cases
that start off…I think the worst ones are the drug related which
create masses and masses of work and often you are not involved on
the investigation side…You might get a few dribbles of information
but often you don’t get that much…So you are ploughing through great
piles of work…It’s a job…it’s what you are there for…but it’s not as
exciting as people might think".
discrepancy may not have been found under a structured or
questionnaire study and demonstrates the effectiveness of an open
ended interview technique. One participant responded to direct
probing of the differences between volume and other crime. It led to
a direct sounding answer: “I don’t argue that
volume and other crimes are consciously treated differently and
indeed the actual process of matching fingerprints is, as stated,
identical, whether it has come from a murder or from a house
burglary” However, it does appear that although
they are treated the same with a consistent level of “commitment”,
and using the same comparison techniques, the end result has
different impact, and the desire to find a match appears to be
stronger depending on the crime severity.
Associated with the Act of Finding a Match
direct job satisfaction and desires, there were lower level
emotional responses associated with finding small areas of
similarity within two fingerprints that corresponded or
determination that two prints matched. There was a wide range of
responses, from descriptions of feeling a “buzz” as a direct
response of matching the prints, to an emotional outburst in one
case. “…that feeling when you know you’ve
identified someone because all the features correlate” “…oh it’s a
buzz. It’s a definite buzz. […]. When you get one, especially from
the search, the buzz is there.” “…I was getting used to turning over
every set of fingerprints I saw because the palm prints are on the
back and thought “heyup, what’s that?”, and it was like “WAHEY!” and
a really, really good, really good feeling”.
that not only are there motivational factors associated with solving
crime but there are direct emotional feelings associated with
finding fingerprint matches. Furthermore there are indications of
emotional responses during the process of matching prints as well,
i.e. before a definitive conclusion has been reached. There are
descriptions of a build up of “recognition”, and increases in
“confidence” and “encouragement”, which appear to
enhance the “feeling of a match”. “I was just beginning to get
the feeling that it was a match…” “…You pick your initial target,
you know you’re first feature you’re going to
look for, and then you look through you prints and you recognize it.
That gives you a little, encouragement, you know, I’ve got something
to focus on, somewhere to start, um, […] and…you know, every time
you see something you recognize your confidence builds in the fact
that it’s a match, and the end point is “can I build my confidence
to absolute confidence”. You know, “can I eliminate all doubt in my
mind whether these two prints came from the same finger, and it’s a
process of eliminating doubt.” This finding
describes minor positive emotional responses of recognition as a
result of seeing areas of agreement during a comparison. There are
small emotional rewards of matching individual targets within the
whole fingerprint before a tipping point is reached.
these recognition events pile up in you brain until you, you, in a
way you’ve got no choice but to come to the conclusion that they
were made by the same source. It just becomes overwhelming and it’s
just like seeing your friend down the pub…’I know who that is’ ”.
by our examiners of the feeling of accumulating evidence until a
specific level of confidence is met confirms the theoretical
decision making threshold, “winner-takes-all", model (33). This
suggests that forensic fingerprint examiners use this type of
decision mechanisms to make their judgments. Specifically that
evidence accumulates over time to a specific, but malleable, level
where a decision can be made, rather than a normative model of
evidence deduction and an objective judgement. Therefore, prints are
not said to match because logical deduction has proven them to, but
that for the examiner concerned, their subjective level of
confidence or their “decision threshold" has been met by the
accumulation of evidence. It should further be noted that it was
reported that different examiners appeared to have different
decision thresholds. A decision maker with a lower threshold will
result in faster decisions as they require less evidence before the
same degree of confidence is met. Whereas, a higher threshold
results in slower decisions as more evidence must be accumulated.
“some people are just naturally slow where everything has to be done
perfectly, they have to dot every ‘I’ and cross every ‘T’, check
every little bit of scrap. Where other people would be a lot more
cavalier about it, but be quicker and perhaps get more idents,… I
don’t know...” “… everyone perceives things
differently …the levels of information they are looking at varies
between person to person…confidence levels vary…I tend to think I am
pretty much middle of the road…I won’t go over the top and count
every single characteristic in a palm impression but at the same
time I am looking to find a suitable amount to satisfy myself.”
how a system which is supposed to be objective can result in
differences of opinion between examiners. The primary concern is
whether or not contextual biases and external pressures might
influence these threshold levels for the finger print examiner, i.e.
to what extent are these threshold levels determined by normative,
objective prescription, or by subjective, context dependant,
mechanisms. Fear There was a strong sense of fear associated
with making mistakes in fingerprint examination. When asked,
examiners for the most part asserted that to make an erroneous match
was the very worst thing an examiner could do insofar as a person
would be wrongly arrested. While there was also an expression of
fear in making a false negative call, there seemed to be less
emphasis placed on this type of error. In fact, some suggested that
misses were just a part of being human. There also appeared to be a
value placed on the fear associated with either a false negative
over a false positive. For example, because generally there seemed
to be a primary fear of making a false positive judgment, this
appeared to weight the attitude of the examiner toward a more
conservative demeanor. “I know everyone is human and you can make
errors but I would probably feel awful like I can’t
do my job properly.” “…I think “is it my judgement that’s wrong…or
someone else’s?"…but then you have to remember that fingerprints is
opinion…it’s not an exact science…its our opinion” “a wrong ident,…you
are doing something badly wrong…That’s what I would be more worried
of doing.” “You should not miss,…should not have a wrong ident…A
wrong ident is out of the question…I don’t think it should happen…It
happens…Unfortunately it happens” “To actually miss an
identification could hurt the individual as much as making an
erroneous identification…But obviously the implications behind the
two will be slightly different…I suppose there is a tendency to
believe that the cardinal sin is a wrong identification…Missed
identifications may not necessarily lead to problems…” “Fear? Only
fear of making a wrong decision…I think. I think that’s the fear. So
you just wanna be sure that you have made the right decision so you
will probably err on the side of safety because its better to let
the ident go than to make the wrong ident” “The management,
certainly when I was training, would make it quite an official
thing…You have to sign a sheet saying you missed it and put any
comments down…The manager who had started it off would put some
comments down and would go down on file so if you did another one
soon afterwards it would be brought out and it would be a far more
serious thing…You weren’t allowed many misses before it got serious
and that’s as a trainee".
was clear from the data recorded that the examiners interviewed
expressed, in general terms, a desire to avoid ambiguity and to see
cases through to conclusion. Some examiners displayed feelings of
frustration at not being able to finish things up. In addition,
there was a desire to account for all the evidence and to seek out a
definitive solution to the casework. In short, there was strong
evidence of a need for closure. “…its annoying…It’s
like ohhhhh…I got that one little bit left"…. “I would like to
finish it up…maybe I’m a bit of a perfectionist occasionally …I need
to complete everything” “Once I start something I like to finish
it…and it’s nice to finish it…and as a fingerprint expert it’s nice
to have a case wrapped up". “You would like to have a result in a
case…i.e.…that the mark’s been identified to a suspect or the mark
has been eliminated…Whereas, the mark’s not being identified or
eliminated is hanging in the air…you would like a result either
way"…. “The chances of being able to account for every single piece
are slim…its nice when you can do it” “You like to…because it clears
the job up…if you identify the eliminee…they could have a
record…have their prints previously on file…at least that is the job
cleared up…and that’s the important thing…”
if there aren’t unnecessary marks on the database…because they are
being searched against unnecessarily …it’s nice to know that that
job is finished…all the marks have been checked and assigned to
whatever outcome and you know you don’t have to revisit that job.”
“It gives you a better sense of closure.”
There were a
number of significant findings as a result of this study. Some
important motivational and emotional factors appeared to be an
integral part of the working life of fingerprint examiners. There
was a considerable amount of pride and satisfaction associated with
the skills they had learnt and used daily. In addition, there was a
significant personal interest in catching criminals or solving
cases, especially when it related to high profile, long running, or
serious crimes. Experts described the process of looking for matches
in emotional terms and, specifically, described matching in terms of
“feeling" and reaching a specific threshold at which they can make a
final determination. Scientific analysis of fingerprints and the
comparison and evaluation of such material has always been assumed
to be an objective process, yet clearly there are subjective
elements introduced by human factors and their interaction with the
methodology for comparing fingerprints.
findings are very important as they indicate specific cognitive
mechanisms. For example, the Madrid bombing case (3,
6), which was a very high profile and important event. The
investigators working on that case were highly motivated to get “a
result" and close the case. That is not to say that they would have
intentionally falsified matching the two prints. Rather, they may
have reached the decision that the two prints matched sooner based
less on evidence that they may have ordinarily have required. The
combination of a strong underlying motivation to find a match or
close the case, as well as smaller emotional feedback, when finding
small similarities between the two prints, might have had an effect
on subsequent information selection and processing which may have
resulted in the decision threshold being lowered. The experts would
feel that they had performed their job accurately and correctly
since a subjective feeling of confidence would have been
experienced. Given that participants generally viewed major crime as
being more rewarding; this may act as an emotional amplifier by
increasing the potency of the emotional rewards and moving them
closer to the threshold at which a conclusion is reached. This would
result in decision thresholds being met with different levels of
evidence depending on the context and the type of crime. If this was
to be the case, then the chance of erroneously matching prints might
increase as a result of context, such as case severity or drive for
closure. That said, there was an expression of fear and consequence
in making an erroneous match. This fear of error may result in more
conservative decision thresholds which would entail incorrect
non-identification conclusions. Examiners seemed to feel that
missing an identification was less important than falsely
identifying an individual. Some examiners acknowledged however that
to have too many false negatives would be detrimental to the
professional standing of any examiner. It is just as important to
understand why examiners miss identifications as it is to understand
how erroneous identifications arise. Both are incorrect conclusions.
area of interest in this study was the apparent need for fingerprint
examiners to achieve closure on casework. While there is existing
literature that suggests that fingerprint examiners are vulnerable
to the effects of context and top down cognitive processes, it is
interesting that there also appears to be a wider
socio-psychological phenomenon evidenced within the fingerprint
profession. Many of those interviewed appeared to make comment
suggestive that they possessed a high need for closure. People with
a high need for closure may have a stronger desire to obtain a
definitive answer, as opposed to uncertainty and ambiguity. People
with a high versus low need for closure may prefer the company of
those with similar attitudes and philosophies and feel positively
disposed toward those who allow for consensus. Similarly those who
require need for closure may feel negatively toward those who
deviate or jeopardise consensus. People with high need for closure
may make correct judgements so long as the cues initially seized
upon were correct. However, people with a high need to avoid closure
may also commit errors if they too readily unfreeze correct
judgements through excessive openness to misleading or irrelevant
information. In other words, fingerprint examiners might be
vulnerable to error through a heightened need for closure that may
either impact upon verification and arbitration discussions by
arriving at an erroneous consensus by associating with ones who are
likely to agree with them, or, conversely, may miss identifications
because they were unable to come to the right conclusion because
they literally looked at the mark for too long and effectively
talked themselves out of it. People under a heightened need for
closure may seize on information appearing early in a sequence
during a fingerprint comparison and freeze on it, ignoring or
unfairly weighting subsequent information within the fingerprints
that may offer an alternative hypothesis. People with high need for
closure may process less information within the fingerprint before
committing to a judgement and generate fewer competing hypotheses to
account for the available data. To put it in terms of the threshold
theory, high need for closure results in a lower decision threshold
and therefore less information is required before the decision maker
can close the case and make a judgement. It is the “seizing and
freezing" (19), which may be central to the notion that contextual
information can bias decision making.
possible that decision making thresholds of fingerprint examiners is
dynamic along an elastic continuum that is dependent upon certain
factors including; the cost of error, motivation to be accurate,
time pressure, the importance of the case, the context in which
evidence is framed, the individual traits of the examiners
themselves, such as need for closure, as well as the environmental
conditions and culture within which fingerprint examinations take
place, such as background noise and interference. It is this
theoretical framework of malleable decision thresholds which might
explain how biasing factors affect the decision process in some
scenarios but not in others. So while contextual influences are
broadly observed in fingerprint analysis and scientific studies, it
will be important to understand at what point contextual bias
impacts upon the actual conclusions of the examiners. Bias and
cognitive influences affect the decision process but not necessarily
the decision outcome. The aim of the above discussion is to
stimulate further research rather than to deliver a final
conclusion. However, this study presents some exciting questions
about the nature of top-down effects and contextual influence and
the possible catalysts that may exacerbate such phenomenon. In
future research it would be valuable to look in more detail at the
concept of need for closure in fingerprint examiners. For example,
need for closure may bias the fingerprint examiners’ choices and
preferences to facilitate attaining closure. Need for closure may or
may not be a generic feature of fingerprint examiners and this will
need to be investigated. If the phenomenon is present, may it be
mitigated or amplified under environmental noise, when the task is
unpleasant or dull or when the individual is fatigued? It might be
the case that need for closure is emphasised and appreciated in the
domain of fingerprint analysis. This may be especially true when
verification protocols suggest that an agreement of opinion is
routinely expected. As with any research there are potential
weaknesses as well as strengths in this study. For example, the
lines of questioning could have gone into more detail about the
correlation between methodological objectivity and how participants
felt this process was affected by the emotions and motivations
highlighted. This could be an area for further study.
What is certain as a result of this study is that fingerprint
examiners not only are emotionally driven and motivated to achieve
results for themselves, their employees the police and wider
society, but also that there are more subtle psychological factors
such as need for closure that exert leverage upon the decision
making thresholds of examiners that may, in the right circumstances
lead to erroneous conclusions should the context and the motivation
be strong enough. Only by understanding these phenomenons will it be
possible to mitigate against future error and methodological
breakdown of fingerprint analysis, as well as design and implement
effective and robust recruitment, selection and training
environments that are able to provide best practice for examiners
and to satisfy public confidence in not only fingerprint examination
but also other forensic domains as well.
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for study interviewing experts about the process of finger print
matching. 1. Greet and give consent/information
form 2. Offer opportunity to ask questions 3. Begin interview
Lettered Questions indicate main questions, the sub questions are
prompts only to be used if needed. This is only a guide any
questions or probes which seem relevant at the time may also be
A) Could you
describe the process of a day to day finger print analysis?
procedure you follow?
ii. What do
you do after that?
iii. Can you
tell me more about that?
how performance is measured?
B) Could you
describe the last time you matched a finger print?
specifics is there anything in particular you remember about the
ii. How did
you feel about that/succeeding in matching the prints?
iii. Can you
describe how you reach that definitive conclusion as to match or
how you feel when you find what you think is a good match and then
you discover anomolies?
C) Could you
describe the last time you didn’t match a finger print?
i. What did
you do after that?
ii. Can you
tell me more about that?
iii. How did
you feel about that/not succeeding in matching the prints?
iv. Is it
possible to have close non matching fingerprints?
D) Could you
think back to a case that you strongly recall
significant a case in which you did or didn’t find a match?
ii. How did
you feel beforehand?
iii. What do
you do after that?
iv. Can you
tell me more about that?
v. How did
you feel about that?
vi. How did
you feel afterwards?
E) Could you
describe a time when you were working on a particularly difficult or
i. How did
you feel beforehand?
ii. What do
you do after that?
iii. Can you
tell me more about that?
iv. How did
you feel about that?
v. How did
you feel afterwards?
F) Could you
describe the sort of day to day pressures you experience?
G) Can you
describe the checks and balances in a bureau that ensure quality and
what ensures mistakes do not occur?
Is a missed
identification worse or better than making an erroneous match? Do
examiners ever disagree on matters of exclusion or identification?
How are such disputes resolved? Have you ever had an identification
disputed? How did you feel? 4. Give debriefing form. 5. Give another
opportunity to ask questions.