How many loci are considered 'core loci' by the FBI for the Combined DNA Indexing System (CODIS)?

The FBI has designated 13 specific loci as 'core loci' for the Combined DNA Indexing System (CODIS). These core loci are essential for forensic DNA testing because they provide a standardized set of markers that allow for reliable comparisons of DNA profiles across different crime scenes and datasets. The selection of these loci is critical for ensuring that the DNA profiles generated are consistent and have sufficient discriminatory power to distinguish between individuals. The 13 loci include a combination of short tandem repeats (STRs), which are known to vary greatly among individuals, making them suitable for use in criminal investigations and paternity testing. This established standard facilitates the sharing of DNA information across jurisdictions, enhances the database's utility, and improves the chances of solving crimes through DNA evidence.