Your DNA is completely unique unless you have an identical twin. However, there are markers in your genetic code that connect you to other people in your family. With the rise in popularity of using genetic testing to determine a family’s national and racial lineage has come an increased desire by law enforcement to use the ever-growing bank of identified genetic profiles to catch those accused of offenses.
In many cases involving unsolved sex crimes, for example, forensic testing of a sample on its own may not produce a suspect, but comparing a test to national databases could help police narrow their search and locate a suspect.
State or federal law enforcement agencies have begun to use databases of genetic information run by public testing companies or have tricked family members related to a suspect into providing genetic samples to help law enforcement determine who DNA ties to the scene of the crime.
Someone else’s DNA can effectively prove a family member’s involvement
Advances in genetic analysis have made it easier than ever before for tests to determine whether two samples have any sort of relationship to one another. There have even been cases where law enforcement agents have targeted multiple family members in the same extended family tree to determine which branch of the family a genetic sample left behind at a crime scene came from.
Police often use misleading statements to convince people to submit their DNA in these early stages of genetic investigation. Anyone facing criminal charges related to family DNA testing will want to very carefully review all of their options for building a criminal defense strategy, including challenging the evidence itself.