Implementation of NGS and SNP microarrays in routine forensic practice: opportunities and barriers

Forensic DNA analysis plays a pivotal role in personal identification, kinship assessment, and criminal investigations, with Short Tandem Repeat (STR) typing via capillary electrophoresis (CE) long established as the gold standard. However, CE-based STR analysis faces notable limitations in multiplexing capacity, the interpretation of degraded or mixed samples, and the resolution of complex kinship relationships. Emerging technologies such as Next Generation Sequencing (NGS) and Single Nucleotide Polymorphism (SNP) microarrays present promising alternatives that can address these shortcomings and expand the scope of forensic DNA testing. Despite their potential, the adoption of these methods in routine forensic practice remains limited due to high costs, technical complexity, and a lack of standardised protocols and legal frameworks. This review critically examines the capabilities, limitations, and current applications of NGS and SNP microarrays in comparison to traditional STR CE profiling. NGS enables STR sequencing and SNP typing with enhanced discriminatory power, better performance with degraded DNA, and improved mixture deconvolution. Conversely, SNP microarrays offer a cost-effective solution for extended kinship testing, Forensic Investigative Genetic Genealogy (FIGG), and phenotypic prediction, though they are less effective with low-quality samples and DNA mixtures. Ethical, legal, and privacy concerns, particularly surrounding the use of Forensic DNA Phenotyping (FDP) and consumer genetic data in FIGG, further complicate their integration into forensic workflows. While significant challenges remain, technological advancements and growing regulatory efforts point towards an achievable path for wider implementation. A hybrid approach that combines STR CE for routine casework with NGS and SNP microarrays for complex scenarios, supported by investments in bioinformatics training, database expansion, and ethical governance, offers a practical strategy for integrating these technologies into future forensic practice.