laboratory is where the essence of forensic science
takes place, with one objective - to deduce all of what
is possible from evidence. Thus, there is the need for
multiple departments, personnel and methods of analysis.
laboratories contain almost all aspects of forensic
science in one place, where skilled scientists
and specialists who focus on specific areas of
forensic science work together to unravel and
solve even the most intricate of crimes. Forensic
laboratories are commonly attached to universities
so the scientists who work there can give students
studying forensics a first hand experience. Large
police departments may have their own forensic
laboratory but otherwise, forensic laboratories
are independently run.
all run following the same basic rules and regulations.
Any item of evidence that enters the lab must never
come into contact with anything that could contaminate
it. Its progression through each of the lab's departments
must therefore be fully recorded so that it can be perused
at any time. Once the sample is in the lab, the most
is always carried out first i.e to verify that the item
is really what it is, before moving onto more expensive,
but precise procedures to discover the evidence the
item might hold. Any tests that may destroy the piece
of evidence are carried out last, after all the other
tests have been completed.
laboratories contain the most up-to-date technology
and techniques for enhancing and analysing fingerprints,
shoeprints and tyre marks. As specific methods of analysing
evidence at a crime scene are not practical, the objects
are recovered and brought into the lab. Below are some
common units found in many major labs.
The polarising light microscope pictured right is often
used for particle identification. Photo courtesy of
In most labs, a unit
commonly known as a 'trace evidence unit' forms an area
where scientists look for clues in evidence such as
hair, fabric, dust, fibre and skeletal remains. Refer
to the 'Every
Criminal Leaves A Trace' section.
chemistry unit is present in any laboratory and
is used to test samples of blood and urine for
alcohol, drugs and poisoning. Chemistry sets are
also used in the analysis of synthetic materials
such medicines, dyes and stains. Specialists in
the area of chemistry also rely on gas
spectrometers and microscopes to identify
The serology unit specializes
in the identification and analysis of bloodstains
and other bodily fluids, as well as DNA sequencing.
The most common of the DNA tests, the polymerse
chain reaction, is now able to be performed
in small laboratories, thanks to advancements
in this area, however, the analysis of mitochondrial
DNA is still only performed in large forensic
Material units are used
to identify and analyse metals, paints, ceramics, soil
and wood in an attempt to trace a crime back to a possible
suspect. The biology unit is in charge of analysing
all biological evidence such a seeds and plants.
units test weapons to see which weapon made the
mark on an object or wounded or killed a person.
To be able to carry out these tests, firearms
specialists study the used bullet cartridges and
use shooting baths to fire weapons, identify the
bullet marks and establish the firing distance.
Photography plays a
vital role in the forensic laboratory, as photography
is used to document crime scene evidence. Processing
resources and dark room services allow specialists in
the area of photography to analyse photographs and bring
the evidence to light.
35mm medium format cameras form the general camera type
used in forensic photography. Photo courtesy of www.morguefile.com.
Large labs also have
and explosives experts as well as specialists in software,
computer data, files, documents, audios and video recordings.
The units available in different labs will vary from
one to the other, however, the need for certain analyses
and the budget of each lab determines the availability
of the departments.
are extremely complex and involve up to hundreds of
people to ensure everything runs quickly and efficiently.
Staff ensures that evidence is correctly booked in,
prepared and stored, cleans and maintains the lab, as
well as servicing the various technical equipment and
keeping it looked after. Testing results from the evidence
is useful in solving one crime, but when added to a
worldwide database, the evidence can be linked to other
crimes that the suspect may have committed.