Fourier-transform infrared spectroscopy (FTIR) is an important analytical technique that examines molecular vibrations associated with chemical bonds. It can help characterize unknown substances, paints, fibers, and polymer materials encountered during forensic investigations. Understanding chemical bonds also supports the analysis of drugs, toxic substances, and other chemical evidence. Such knowledge contributes to the interpretation of laboratory findings and the scientific evaluation of materials collected during investigations. Therefore, chemical bonding is not only a theoretical topic but also an essential foundation for forensic chemical analysis and reliable evidence interpretation. Sustainable Development Goal: SDG 16 – Peace, Justice and Strong Institutions. Understanding chemical bonding supports reliable forensic analysis and contributes to evidence-based justice.