Forensic Sciences and Criminalistics
What the exam tests
Forensic science questions test the application of scientific methods to evidence: fingerprinting, ballistics, DNA, toxicology, and document examination. The delegate must know what each technique can and cannot prove.
Core concepts
- Papiloscopia: fingerprint patterns (arches, loops, whorls) and the pontos característicos used for identification.
- Balística: caliber, rifling, and the comparison of projectiles; the difference between calibre nominal and calibre real.
- Genética forense: DNA profiling, autosomal and Y-chromosome markers, and the interpretation of mixtures.
- Toxicologia: detection of substances in biological samples and the limits of postmortem interpretation.
- Documentoscopia: forgery, erasures, and the analysis of inks and papers.
- Local de crime: isolation, photography, and collection.
Traps
- DNA match is not absolute proof of authorship; it identifies biological material.
- Calibre nominal (commercial designation) differs from calibre real (barrel diameter).
- Fingerprints are individual, but the number of matching points required is a technical, not legal, criterion.
- Toxicology: postmortem redistribution can alter concentrations.
Rule of thumb
For each technique, ask: what does it identify, and what is its limit? Fingerprints identify a person; ballistics links a weapon to a projectile; DNA links biological material to a source; toxicology links a substance to a body.
Worked example
A projectile found at the scene has rifling marks compatible with a seized weapon. The expert concludes compatibility, not certainty, unless the marks are sufficient for individual identification. The exam expects the distinction between class characteristics and individual characteristics.