This is a good overview of DNA forensics, genetic genealogy, and existing databases like GEDmatch (Verogen).See Othram: the future of DNA forensics (2019):
@15:35 "Multiple law enforcement agencies have said that this is the most revolutionary tool they've had since the adoption of the fingerprint."
The existing FBI standard (CODIS) for DNA identification uses only 20 markers (STRs -- previously only 13 loci were used!). By contrast, genome wide sequencing can reliably call millions of genetic variants.
For the first time, the cost curves for these two methods have crossed: modern sequencing costs no more than extracting CODIS markers using the now ~30 year old technology.
What can you do with millions of genetic markers?
1. Determine relatedness of two individuals with high precision. This allows detectives to immediately identify a relative (ranging from distant cousin to sibling or parent) of the source of the DNA sample, simply by scanning through large DNA databases.
...More Othram posts.