Crime Scene Investigation (CSI) involves the complex and rigorous examination of evidence which ultimately ends with a criminal prosecution. This work is carried out by Crime Scene Investigators who are trained in the identification, recovery and recording of evidence from a multitude of different crime scenes – including buildings, people (be that victim, suspect or witness), transport or areas of land or water.
There are three key principles involved in Crime Scene Investigation, which we have outlined below:
Principle 1: Locard’s Exchange Principle (1928)
‘Every contact leaves a trace’
Professor Edmond Locard (1877-1966) was a French scientist credited for setting up the first modern crime laboratory in Lyon, France. In addition to this, he theorised that every contact a criminal makes ultimately leaves crucial evidence behind – resulting in exhibits that Crime Scene Investigators will be able to analyse.
“Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibres from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more bear mute witness against him.”
If there is always exchange between materials, three factors are of prime importance:
- Can the exchange be detected, recorded and quantified?
- Is the exchange discriminating?
- Can the importance of the link be communicated to a jury within the bounds of the law?
Principle 2: Sequential Examination
To ensure that the data recovered during an examination can be optimised, it is essential that the sequence of examination proceeds from non-invasive to most invasive.
Sequential examination involves working through evidence in a logical or consecutive order, and the non-invasive to most invasive approach would aid with vital preservation of evidence.
It is also important to note that you cannot seize everything.
Principle 3: Continuity and Disclosure Material
There is a burden placed on the prosecution to preserve all material produced from an investigation. This material is then made available to the defence, to ensure that accurate cross-examination can be conducted.
Complete and accurate record keeping is essential, for both independent experts as well as police personnel.
You’ll learn this on the first day in our range of comprehensive CSI Initial/Stage 1 training, with the rest of the course covering:
- The role of the CSI and its relation to other key policing roles
- Core evidence recovery skills including: packaging, exhibiting, exhibit selection, presumptive blood testing, swabbing, packaging, storage, powder and chemical fingerprint examination
- Record and evidential photography
- Risk assessment, welfare and evidence recovery plans
- The National Intelligence Model – gathering, assessing and disseminating intelligence
- Interview, liaison, and interpersonal skills
- Crime scene sketching and planning
- Niche evidence and scene awareness for fire scenes, firearms and entomology
- Digital forensics on the crime scene
- Statement writing and court deportment
Alecto Forensics is a UK leading provider of professional training services, delivering expert training to law enforcement personnel across the UK.
We offer a wide variety of bespoke training solutions, including: Crime Scene Investigation (Stage 1 and 2), Crime Scene Management, and Continuing Professional Development.