The Application of DNA Profiling in Criminal Investigations: Methods, Challenges, and Forensic Implications

DNA profiling has become an important component of modern forensic science and criminal investigation. Biological materials such as blood, saliva, semen, hair, tissue, and skin cells can provide genetic information that may assist investigators in associating individuals with crime-scene evidence, identifying unknown persons, and revisiting unsolved cases. Short tandem repeats (STRs) remain central to forensic DNA profiling because variation among STR markers provides high-resolution information for human identification. The investigative value of DNA evidence, however, depends not only on laboratory analysis but also on proper collection, preservation, contamination prevention, interpretation, and statistical evaluation. Modern forensic practice is increasingly incorporating next-generation sequencing (NGS), single-nucleotide polymorphisms (SNPs), mitochondrial DNA analysis, and computational approaches. At the same time, increasingly sensitive DNA methods create challenges involving complex mixtures, low-template DNA, contamination, interpretation, privacy, and the appropriate use of genetic databases. This paper examines the application of DNA profiling throughout criminal investigations, evaluates its evidentiary value and limitations, and discusses emerging technologies and ethical considerations affecting future forensic practice.