I took a genomics class. We had a guest lecture by: Frederick R. Bieber about medical Forenics. Fascinating stuff. Its interesting the way they try to identify

I took a genomics class. We had a guest lecture by: Frederick R. Bieber about medical Forenics. Fascinating stuff. Its interesting the way they try to identify people is they pick 13 locations (more as of this year, the article says 16 locations for england) then count what are known as "Short tandem repeats"(STR). These STR markers exist on many chromosomes and are short sequences that repeat, everyone has a different count. (there is a standard for these locations in the US called CODIS: http://strbase.nist.gov/fbicore.htm http://strbase.nist.gov/fbicore.htm) If you have good reads the probability of a random match is in 1 in 594 trillion. Its complicated as the DNA can degrade and the reads can be not so good. Some places allow Forensic DNA analysis by data mining, in which case you may find relatives of a criminal. Some states require felons DNA to be added to the database. This can be searched though its controversial and familial searches are blocked by some states. One case helped by this was Lonnie Franklin Jr. aka the "grim sleeper" who took a long time to apprehend. https://en.wikipedia.org/wiki/Grim_Sleeper https://en.wikipedia.org/wiki/Grim_Sleeper "Police had found no exact match between DNA found at the crime scenes and any of the profiles in California's DNA profile database, so they searched the database for stored profiles that demonstrated sufficient similarity to allow police to infer a familial relationship. They found similar DNA belonging to Franklin's son, Christopher, who had been convicted of a felony weapons charge. " Exonerations are possible using dna too: http://www.brandeis.edu/investigate/innocence-project/dennis-maher.html http://www.brandeis.edu/investigate/innocence-project/dennis... DNA analysis is just a tool, it can also lead to post conviction exonerations. I think its best used a evidence for building a case, not having the whole weight of the case on just DNA evidence.