Applications of Nanotechnology in Forensic Evidence Detection and the Analysis of Trace Chemical Residues Nanotechnology has emerged as a promising field in the advancement of forensic science because of its ability to detect extremely small quantities of chemical and biological substances that may be present at crime scenes. The unique physical and chemical properties of nanomaterials have contributed to the development of analytical methods with improved sensitivity and selectivity, enhancing the examination of trace evidence and the identification of its components. Many forensic applications rely on metallic nanoparticles, such as gold and silver nanoparticles, as well as metal oxide nanomaterials, due to their distinctive optical and surface properties. Silver nanoparticles, for example, are widely investigated for use in surface-enhanced Raman spectroscopy (SERS), a technique that amplifies the Raman signals of certain molecules and enables the detection of compounds at very low concentrations. One important application of this technique is the detection of trace chemical residues, drugs, and other compounds associated with forensic evidence. Chemically modified nanostructured substrates can also be developed to improve selectivity toward specific target compounds, potentially helping investigators distinguish between samples with similar overall compositions. Nanomaterials are also being investigated for the development of improved methods for visualizing latent fingerprints. Certain nanoparticles can interact with or bind to components of fingerprint residues, enhancing the visibility of ridge details, particularly on surfaces that are difficult to examine using conventional techniques. The effectiveness of these applications depends on the type of nanomaterial, the nature of the surface, and the conditions under which the fingerprint has been deposited and preserved. In the field of biological evidence, nanosensors can be used to detect specific biomarkers, including certain proteins and nucleic acids. These sensors operate through molecular recognition interactions or optical and electrical changes that occur when a target substance binds to the sensor surface. However, their forensic application requires careful validation of sensitivity, selectivity, and potential interference from other components in real samples. Nanotechnology also enables the development of chemical sensors for the rapid detection of toxic substances, drugs, and volatile organic compounds. These sensors may be integrated into portable devices for preliminary screening at crime scenes. Important findings should subsequently be confirmed using validated laboratory techniques, such as gas chromatography–mass spectrometry (GC-MS) or liquid chromatography–mass spectrometry (LC-MS). Another promising direction is the integration of nanomaterials with artificial intelligence. Signals obtained from nanosensors and spectroscopic measurements can be processed using machine-learning algorithms to classify samples and identify subtle chemical patterns. This integration may improve screening speed and sample discrimination. Nevertheless, reliable databases, independent validation, and careful evaluation of error rates are essential before these methods can be adopted in forensic investigations. Despite their considerable potential, nanotechnology-based forensic methods face several challenges, including nanomaterial stability, reproducibility of synthesis, matrix effects, possible contamination, and the need to validate analytical procedures before their use in legal investigations. Appropriate safety measures are also necessary when handling nanopowders and nanoparticles. The integration of nanotechnology with analytical chemistry, spectroscopy, and artificial intelligence represents a promising direction for the development of modern forensic laboratories. These advances may improve the detection of trace chemical residues and enable the design of more sensitive analytical sensors.