Forensic sciences have witnessed significant qualitative advancements in recent decades, driven by progress in biological technologies—foremost among them genetic fingerprinting (DNA Fingerprinting), which has become one of the most accurate tools for solving crimes and identifying offenders. 1. Definition and Scientific Nature of DNA Fingerprinting Definition DNA fingerprinting refers to the unique genetic characteristics found in human cells, identified through the analysis of DNA using advanced laboratory techniques. It is characterized by: • Stability throughout an individual’s lifetime. • Exceptional uniqueness, with matches occurring only in extremely rare cases such as identical twins. • The ability to be extracted from any living or dead cell in the body. Scientific Basis The analysis of DNA fingerprints relies on the study of: • Short Tandem Repeats (STRs). • Nucleotide sequencing. These indicators allow for distinguishing between individuals with accuracy reaching billions of possible combinations. Sources of DNA Samples can be obtained from: • Blood, saliva, hair, bone, and teeth. • Various body tissues. • Biological residues found at crime scenes, such as blood stains, skin fragments, and bodily fluids. ⸻ 2. Evidentiary Value of DNA Fingerprinting Accuracy and Certainty Studies show that the probability of two unrelated individuals sharing identical DNA fingerprints is extremely low, making DNA evidence nearly conclusive. Objectivity Unlike confessions or eyewitness testimony, DNA evidence is: • Not influenced by psychological factors. • Not dependent on human memory. • Resistant to manipulation. Applications DNA fingerprinting is used in: • Murder, rape, and assault investigations. • Victim identification in disasters. • Paternity and kinship cases. • Identifying unknown bodies. ⸻ 3. Legal Validity in Criminal Evidence Acceptance in Legislation Most Arab and international legal systems have recognized DNA fingerprinting as a valid means of proof, including: • Egyptian law. • Moroccan law. • Gulf legal systems. • The Arab Model Law. Its acceptance is conditioned on: • Proper sample collection. • Maintaining an unbroken chain of custody. • Analysis by accredited laboratories. Requirements for Validity The reliability of DNA evidence depends on: 1. Legality of sample collection without violating bodily integrity. 2. Confirming the attribution of the sample to the individual. 3. Expertise of the analysts conducting the test. 4. Presenting a clear technical report to the court. Judicial Position Modern courts tend to consider DNA evidence: • Conclusive in cases of complete match. • Supporting when combined with other evidence. ⸻ 4. Ethical and Legal Challenges Genetic Privacy The collection and storage of DNA raise concerns regarding: • Bodily integrity violations. • Misuse of genetic data. • Creation of DNA databases without adequate safeguards. Possibility of Error Despite high accuracy, errors may occur due to: • Sample contamination. • Improper storage. • Laboratory incompetence. Zahraa Emad Al-Mustaqbal University The First University in Iraq.