ng
an
P
tistr
ty of
sity
a r t i c l e i n f o
Article history:
Received 22 December 2008
Received in revised form 22 July 2009
Accepted 25 October 2009
Available online 19 January 2010
Keywords:
a b s t r a c t
bruise to occur two things must happen: Once blood is within the tissues, the body launches an inflam-
matory response to degrade and remove it.6,10 Macrophages phag-
ocytose the red cells and the haemoglobin is degraded.
Haemoglobin is one of the dominant absorbing chromophores,
determining the colour of skin,11,12 and its appearance varies
(red/blue/purple) depending on its oxidative state and depth with-
in the skin.12–14 It is the biochemical breakdown of the Haemoglo-
bin in red cells that accounts for the colour changes that may be
observed within a bruise.6 Haemoglobin degradation is catalysed
* Corresponding author. Address: Cameron Forensic Medical Sciences, Clinical
Pharmacology, Barts and The London, London EC1M 6BQ, UK. Tel.: +44(0)20 7882
3401, mobile: +44(0)7802 563 223; fax: +44(0)20 7882 3408.
Journal of Forensic and Legal Medicine 17 (2010) 143–149
Contents lists availab
Journal of Forensic a
journal homepage: wwE-mail address: p.vanezis@qmul.ac.uk (P. Vanezis).1. Introduction
The evaluation of any tissue injury, is an essential component of
forensic practice.1,2
Forensic experts are frequently asked to comment on the age of
bruises, in cases such as child abuse, assault and sexual assault.
Their interpretation may have significant medico-legal conse-
quences,3 including the incrimination or exclusion of a suspect as
the perpetrator of a crime.
A bruise is a focal discoloration of the skin,4 caused by an extra-
vascular collection of blood under an intact epidermis, following
trauma to the body by the impact of a blunt instrument.1,5 For a
(i) The skin and/or underlying tissues must be sufficiently
crushed or stretched by a mechanical force for the small ves-
sels within to be ruptured, without breaching the surface of
the skin.6,7 For this to occur, the trauma must be caused by a
blunt instrument, otherwise the skin surface will be cut, and
the force must not be so great that the elastic limit of the
skin is exceeded and the skin is ‘split’, forming a laceration.7
(ii) Blood must leak from the damaged vessels into the sur-
rounding tissues.6 This requires sufficient pressure within
the blood vessels to expel the blood,8 and thus a bruise, in
almost all cases, is an ante-mortem event.9Bruising
Skin
Ageing
Forensic experts1752-928X/$ - see front matter  2009 Elsevier Ltd a
doi:10.1016/j.jflm.2009.10.002Introduction: Forensic experts are frequently asked to comment on the age of injuries and interpretation
may have significant medico-legal consequences. The purpose of this study is to determine the accuracy
with which forensic experts can visually age a bruise from photographs produced under standard condi-
tions.
Methods: Bruises were produced on the upper arms of 11 subjects by a suction pump. Sequential photo-
graphs were taken daily until they were no longer visible to the naked eye. Fifteen forensic experts who
did not know the age of the bruises were asked to estimate their ages and also to place them in chrono-
logical order.
Results: Hundred and thirty-two images of 25 bruises were produced, ranging from 0 to 209 h in age.
There was considerable inter- and intra-observer variability in accuracy (median difference between
the estimated age and the real age = 26.0 h (95% C.I. 24.0–31.0 h). There was greatest accuracy for bruises
photographed between 0 and 12 h. No significant differences were seen between male and female
observers (p = 0.553) and performance was also unaffected by the age of the observer (p = 0.160). Of
the bruise images placed in chronological order >80% of the observers made between 0 and 2 errors.
Conclusion: Bruise age estimates by forensic experts, from photographs, are unreliable. However, it
appears that the vast majority of observers are better able to place bruises from the same subjects in their
chronological order.
 2009 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.Original Communication
Visual assessment of the timing of bruisi
M.L. Pilling BMedSci (Hons) (Medical Student) a, P. V
D. Perrett PhD CChem FRSC (Professor) c, A. Johnston
aBarts and The London School of Medicine and Dentistry, University of London, UK
bCameron Forensic Medical Sciences, Barts and The London School of Medicine and Den
cBioanalytical Science, Barts and the London School of Medicine and Dentistry, Universi
dClinical Pharmacology, Barts and The London School of Medicine and Dentistry, Univernd Faculty of Forensic and Legal Mby forensic experts
ezis OBE PhD FRCPath (Professor) b,*,
hD FRCPath (Professor) d
y, University of London, UK
London, UK
of London, UK
le at ScienceDirect
nd Legal Medicine
w.elsevier .com/jflmedicine. All rights reserved.

observer. Photographs are taken at the time of examination, in or-
of the force applied.6 The appearance of a bruise will depend on:
ception is, by nature, very subjective and will vary with: the ‘nat-
assessed for the presence of particular colours. The study con-
2.4. Unreliable photographic colour reproduction
If bruise age estimates are to be made from photographic
images, then the colours within the photographs must represent
the colour within the bruise. However, photographic colour repro-
duction is notoriously unreliable and depends on factors such as:
the camera, the ambient lighting and the printer. The study con-
ducted by Munang et al. also identified intra-observer variability
between colour descriptions of bruises in vivo and those made
from a photograph.15
The photographic study by Stephenson and Bialas used 1 expe-
rienced ‘blind’ observer to estimate whether the bruises in the pic-
tures were fresh (<48 h), intermediate (48 h to 7 days) or old
(P7 days). The estimates were found to be ‘unreliable’.18 A more
recent study assessed the accuracy of physicians examining bruises
in vivo, where features other than colour could contribute to their
interpretation. It showed that emergency paediatricians, experi-
(Fig. 2). All images included a colour scale, to minimise colour dis-
tortion, and a centimetre scale. All images were taken of the bruise
and Legal Medicine 17 (2010) 143–149cluded that a bruise containing the colour yellow must be older
than 18 h (although its absence did not suggest that the bruise
was younger than 18 h).17 The second study, which looked at
images of 50 accidental bruises in children, did not find a yellow
hue in any bruise under 24 h old.18
2.3. Variability in the threshold at which individuals can perceive
yellow
A later study by Hughes et al., digitally modified images of
bruises to contain increasing amounts of yellow, from 2% to 20%.
The point at which each observer could perceive yellow was re-ure and quality’ of the incident light, the nature of the
interaction between light and matter; the background and also
the observer’s interpretation of the light waves detected by their
visual system.19 A study conducted by Munang et al., in 2002,
found that there was significant inter-observer variability in colour
descriptions of bruises.15
2.2. All colours except yellow appear to be unrelated to age
Two photographic studies have found that the only colour
which has any bearing on the age of a bruise is yellow.17,18 Other
colours may be apparent at any time. Langlois and Gresham con-
ducted a study using 369 photographs of bruises of known age
on 89 subjects aged 10–100 years. The photographs were visually Factors relating to the victim e.g. age, sex, % body fat, bleeding
diatheses and skin colour.
 Factors relating to the infliction of the bruise e.g. force applied,
site of infliction and type of weapon.
2.1. Subjectivity of colour perception
Rather than being an intrinsic property of an object, colour is
the sensory perception of the interaction between that object
and the constituent wavelengths of the incident light.19 Colour per-der to illustrate the findings and because it may not be possible to
re-examine at a later date. However, previous research has identi-
fied many potential problems with this method, leading to signifi-
cant doubts in the accuracy with which forensic experts are able to
date bruises.15–18
2. Variability in bruise appearance
The development and resolution of a bruise, in terms of its
appearance, is extremely variable, both between individuals and
within the same person. In general, the greater the damage to
the blood vessels, the bigger the bruise, however, the size and
intensity of the bruise does not necessarily indicate the strengthby Haem-oxygenase producing Biliverdin (green), Carbon Monox-
ide and an Iron atom.6,10 The Iron atom released forms a complex
with the protein Ferritin to produce Haemosiderin (brown).10 Bili-
verdin is then rapidly metabolised to Bilirubin (yellow).10
Currently, the ageing of a bruise is made primarily by observing
the colours within it, and using the experience and expertise of the
144 M.L. Pilling et al. / Journal of Forensiccorded. The study identified variability between individuals in
the threshold for the perception of the colour yellow and also
showed that the ‘ability to perceive yellow declines with age’.16site only and were, therefore, non-identifiable.
When possible, sequential photographs were taken daily until
the bruise was no longer visible to the naked eye. The camera set-
tings were kept constant and the images were taken under stan-
dard ambient lighting conditions.enced in examining injuries in children, were able to age bruises
to within 24 h of the actual age less than 50% of the time.20
The purpose of this study was to determine the accuracy with
which forensic experts can visually age a bruise from photographs
produced under standard conditions.
3. Methodology
Healthy adult Caucasian subjects were recruited from the inves-
tigators and senior members of academic staff. Participants in-
flicted bruises on themselves by applying suction to the surface
of the skin. This was achieved using a mains operated suction
pump connected to the barrel of a 30 ml syringe by tubing
(Fig. 1). The plunger of the syringe was removed and the open
end of the barrel was applied to the anterior aspect of the upper
arm for a total of 15 min. This produced uniform circular bruises
3 cm in diameter.
Upon removal of the suction pump, photographs were taken
immediately (Time 0), under standard ambient lighting conditions
using a digital single-lens reflex camera (Canon EOS 350D) with an
EFS 18–55 mm lens and a macro ring-flash (Canon MR-14EX)Fig. 1. Bruise production.