How Your DNA—or Someone Else's—Can Send You to Jail | Electronic Frontier Foundation
Although DNA is individual to you—a “fingerprint” of your genetic code—DNA samples don’t always tell a complete story. The DNA samples used in criminal prosecutions are generally of low quality, making them particularly complicated to analyze. They are not very concentrated, not very complete, or are a mixture of multiple individual’s DNA—and often, all of these conditions are true. If a DNA sample is like a fingerprint, analyzing mixed DNA samples in criminal prosecutions can often be like attempting to isolate a single person’s print from a doorknob of a public building afte...
Source: eff.org