Courtesy Genelex

The public has always been captivated by the drama that occurs in the courtroom. There is even a whole channel, CourtTV, devoted to showing real court cases as they wend their way through the legal system. TV shows and movies depict passionate attorneys sparring verbally as they fight to convict or acquit the accused. However, the most tense moments of a criminal trial are likely those that go unseen: the jury deliberations.

After both sides present their evidence and argue their cases, a panel of jurors must weigh what they have heard and decide whether or not the accused person is guilty as charged. This can be difficult. The evidence presented is not always clear-cut, and sometimes jurors must decide based on what a witness says they saw or heard. Physical evidence can be limited to strands of hair or pieces of fabric that the prosecution must somehow link conclusively to the defendant.

What if there were a way of tying a person to the scene of a crime beyond a shadow of a doubt? Or, more importantly, what if you could rule out suspects and prevent the wrong person from being locked up in jail? This dream is beginning to be realized through the use of DNA evidence. In this issue of HowStuffWorks, we'll look at how DNA "fingerprinting" works and what DNA evidence can be used for.