Services
Marks and chemical traces
Marks
LGC's Marks services encompass all kinds of
marks including shoe marks, tool and weapon marks, marks made as
the result of manufacturing processes, hand and finger marks and
marks made by feet – including inside shoes.
A wide range of different chemical, lighting
and imaging enhancement techniques are used to extract the maximum
amount of information from marks and improve the extent to which
suspect marks can be compared with reference marks from known
sources.
Sometimes these techniques help to indicate or
confirm what substance created the mark and this can provide
further avenues for investigation. For instance, marks made
in blood will provide additional opportunities to reveal links with
individual people through DNA testing, whereas those in soil could
indicate associations with specific places.
As a full service supplier, LGC Forensics is
uniquely positioned to recognise and take advantage of all such
opportunities.
Marks services can be accessed as part of a
rapid screening and intelligence service, such as shoe marks in
volume crime cases or manufacturing marks on the types of small
polythene bags featuring in drugs supply cases.
Alternatively, they can form part of more complex investigations
when they can be combined with any other type of forensic expertise
to meet the needs of individual cases.
Chemical traces
LGC has at its disposal a powerful armoury of
analytical techniques and methodologies it can call upon to
determine the chemical composition of anything that might be
required in a forensic context.
There are two main types of chemical trace of
forensic interest: small particles and liquids or residues of
them. The most commonly encountered types of particles are
glass, paint, other building materials and plastics from breaking
and entry into buildings, vehicle accidents and criminal damage and
textile fibres which can be exchanged between clothing of people
who come into physical contact with one another.
LGC Forensics' scientists are interested not
only in the presence of these sorts of particles, but also in their
numbers, types and distribution. This information is critical
to determining how, when and where an incident might have
happened.
LGC scientists pioneered the introduction of
‘fibre mapping’. In a number of cases this has allowed the
precise distribution of textile fibres which could have come from a
suspect’s clothing to be plotted on the victim’s body and the
information then linked to wound sites and other aspects of the
case to provide a full picture of what is likely to have happened.
Liquid traces include petrol and other
accelerants used in arson attacks, and linking this type of
evidence to sites of burning at the scene, scorch marks on
clothing or burns on those who might have been responsible. CS
sprays and other noxious chemicals used in attacks on people also
fall into this category.
