Spend enough time in DC’s courtrooms and you’ll hear plenty about DNA evidence. From swabs of guns, knives, forks, caps, and more to the drawing of blood or swabbing of a defendant’s cheek, it came seem as if DNA plays a role in nearly every case.
The BBC this week tackled the issue of DNA evidence in a report on upcoming changes to the national DNA index system used by the FBI.
The importance of [the 13 genetic markers used to develop DNA profiles of offenders] was demonstrated in the case of a British man arrested in 1999. His DNA profile matched that collected in a burglary when compared at six genetic loci.
The suspect spent several months in jail before his lawyer demanded a 10-marker re-test. The suspect differed from the burglary suspect at one of the four additional markers and was set free.
While the probabilities of such chance matches between unrelated individuals are relatively small, they increase as DNA databases grow in size.
That’s why the FBI wants to increase the number of genetic markers the system uses, said the BBC.
Read more about the United States’ DNA evidence system and how it’s changing in the BBC’s report.