What is forensic science?

Forensic science simply means that scientific procedures are being applied to legal problems. Virtually all fields of science touch upon this discipline.

Proof of criminal charges

Not long ago, proof of criminal charges depended mainly on eyewitnesses and other subjective means. With scientific advances, objective evidence has taken on a greater role in criminal trials.

Governments rely increasingly on science to help enforce a growing number of regulations.

Because science is now used routinely in litigation, various groups, including lawyers, judges, enforcement officials, and the public, need to know what forensic science can - and cannot - do.

Forensic science is used to enforce laws and government regulations and statutes, to resolve disputes, to assess blame and establish responsibility, and to enhance public safety.

Forensic science involves the collection of information about the physical characteristics, chemical composition and occurrence of materials of forensic interest. It looks at the scientific association between such samples, based on their origins, manufacture, packaging and distribution characteristics.

Chemical fingerprinting

Every time we enter or leave a room we potentially leave behind evidence that we were there. Examples are biological samples such as hair, blood, saliva, urine, or seminal fluid, and other physical evidence such as fibres, or particulate matter including glass fragments and paint chips. Fingerprints may also be left behind.

Forensic science relies upon chemical and physical methods of analysis to create "fingerprints" or "signatures" of people.

Chemical fingerprinting techniques and sample association methods are generally far more effective in excluding an association than establishing a connection between samples.

To confirm an association, all points of comparison must be identical, which usually requires exhaustive analysis and a thorough understanding of the sample.To show that samples are different, it's enough to establish a single point of dissimilarity.

The traditional disciplines of forensic science include:

• Toxicology (study of alcohol and drugs)
• Serology (study of blood and other biological fluids)
• Questioned document examination (examination of documents, handwriting comparison, study of inks, typewriter imprints, counterfeiting etc.)
• Forensic chemistry
• Firearms identification and ballistics (study of marks and striations on bullets)
• Hair and fibre analysis
• Pathology
• Odontology (study of bite marks, teeth structure)

Other specialties include

• Disaster identification (e.g., identifying bodies, and cause of death)
• Analysis of lip prints (cheiloscopy)
• Forensic engineering
• Meteorology (impact of weather on a case)
• Blood spatter identification
• Voice print analysis
• Retinal scanning (e.g., for identification purposes)
• Forensic entomology
• Forensic anthropology