Criminalistics

Criminalistics is the scientific discipline that applies physical and chemical methods to the analysis of evidence in criminal investigations. It focuses on the examination, comparison, and interpretation of trace materials collected from crime scenes, vehicles, laboratories, and victims or suspects. As a core component of forensic science, criminalistics seeks to establish links between people, objects, and events in a manner that is scientifically objective and legally admissible.

The field emerged in the 19th and early 20th centuries with the creation of police laboratories and the work of pioneers such as Edmond Locard, whose exchange principle posits that every crime involves an exchange of materials. Over time, advances in chromatography, spectroscopy, microscopy, DNA analysis, and digital imaging expanded the range of evidence that could be analyzed and interpreted.

Practitioners collect and preserve evidence, maintain chain-of-custody, and perform laboratory analyses to identify substances, determine age or origin, or compare samples to known standards. Common areas include biology and DNA analysis, toxicology, trace evidence (fibers, hairs, glass, soil), firearms and toolmark identification, fingerprint examination, handwriting and document analysis, and impression evidence such as shoe/tire marks. Modern practice often employs instrumental techniques such as GC-MS, FTIR, LC-MS, microscopy, and computer-based image analysis. Results are presented to investigators and, when disputed, as expert testimony.

Quality assurance, accreditation, and peer review underpin reliability. The field intersects with related disciplines such as digital forensics, pathology, and anthropology. Ethical considerations, limitations of evidence interpretation, and the possibility of inconclusive results are acknowledged in court. Education typically involves specialized degrees in forensic science or criminalistics, with ongoing professional certification and collaboration with law enforcement agencies.