Dr. Lemos,Forensic Scientist and Head of the Forensic Toxicology Section (Analytical Unit ) at St George’s Hospital Medical School   London writes about the development and practice of forensic science ...

In absolute terms, the phrase ‘forensic science’ means science that is applied to legal matters. The word ‘forensic’ itself originates from the Latin word ‘forum’ which during the Hellenistic and Roman times was the general assembly where all facts of criminal or disturbing behaviour were discussed in the open and verdicts were reached regarding the suspects involved.

In modern times, forensic scientists are highly specialised individuals who get involved with the investigation of crimes and accidents.  They do so by focusing on the recognition, identification and individualisation of physical evidence at the scene of interest so that they can enable themselves to offer the best possible reconstruction of what took place to the police, solicitors, judge or to the members of the jury.

A day in the life of a forensic scientist may include the examination of hairs, fibres, paint, soil, blood, semen or other bodily fluids, plant and animal matter, weapons and tools and their impressions, questioned documents, etc. These and many more items of physical evidence are examined in order to:

Forensic scientists, like most other pure scientists, heavily rely on the scientific method for their work. The first step is the observation and collection of data. 

Forensic scientists always look for data either at the scene or in the laboratory – physical evidence that needs to be recognised, protected and collected. The next step is the conjecture of the collected data  – where physical evidence is analysed using some basic tests. Once forensic scientists have completed this step, they may formulate a hypothesis as to what this physical evidence is and how it came to be where it was discovered. 

The next step is the testing of this hypothesis – which usually results in minor or major adjustments of the initial hypothesis. If the revised hypothesis can than withstand testing from all different angles and scientists and can account for all the data observed, then it becomes a theory

Thus, forensic scientists always present their theory as to what happened at the scene based on the physical evidence they examine.

In the United Kingdom, on-the-job training of forensic scientists has extensively been used but there also exist several higher education institutions where one can formally be trained in forensic science at an undergraduate of postgraduate level. Both these routes into forensic science are well established and are considered as complementary. 

Training, experience and co-operation are all needed if we are to continue building on what pioneers such as Locard from France and Kirk from the USA have started in the field of forensic science.

   © Dr NP Lemos 2001 (nlemos@sghms.ac.uk)


For information on training in forensic science follow this link ...Forensic Science Educational Resource Homepage