Forensic Chemistry and Its Role in the Analysis of Physical Evidence in Criminal Investigations Forensic chemistry is a branch of applied chemistry concerned with analyzing evidence related to crimes and identifying substances found at crime scenes, such as drugs, poisons, paints, glass, and residues of flammable materials. The forensic analysis process begins with collecting and preserving samples using appropriate methods to prevent contamination and ensure accurate results. The samples are then subjected to qualitative analysis to identify the substances and quantitative analysis to determine their concentrations or amounts. Forensic laboratories rely on modern analytical techniques, such as Gas Chromatography–Mass Spectrometry (GC-MS), Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS), Fourier Transform Infrared Spectroscopy (FTIR), and Ultraviolet–Visible Spectroscopy (UV-Vis), to detect and identify chemical compounds with high accuracy. These techniques are used to analyze drugs and poisons in biological samples, compare paints and glass fragments, and detect residues of flammable materials at fire scenes. This helps investigators interpret evidence and establish links between samples and criminal incidents. The reliability of forensic results depends on instrument calibration, the use of standard materials, prevention of sample contamination, and proper documentation of all stages of evidence collection, preservation, and analysis. Advances in modern analytical techniques have improved the sensitivity and accuracy of chemical analysis, making forensic chemistry an essential tool in supporting criminal investigations and providing scientific evidence that helps establish the facts.