how many core CODIS STR loci are commonly used for the investigations and prosecutions of criminal cases?

The Combined DNA Index System (CODIS) typically utilizes 13 core Short Tandem Repeat (STR) loci for criminal investigations and prosecutions. These loci were determined by the FBI to provide a standard set of markers for DNA profiling, helping in identifying individuals and connecting them to biological evidence.

Explanation:

1. Core Loci: The 13 core loci include specific regions of the DNA where short sequences are repeated. The likelihood of these sequences being identical in unrelated individuals is very low, making them highly useful for forensic analysis.

2. Standardization: The use of a standard set of loci allows for consistency across laboratories and jurisdictions. This standardization is crucial when DNA evidence is analyzed in different locations or populations.

3. Legal Framework: The CODIS system is used in the United States for criminal investigations, and its loci are widely accepted in courts for genetic identification, ensuring that evidence can be reliably presented to support prosecutions or exonerations.

These 13 loci form a key part of forensic DNA analysis, providing valuable information for law enforcement and the criminal justice system.