Transcript for How cutting-edge DNA technology helped break open 1992 cold case
Reporter: It was a crime that shocked Lancaster, Pennsylvania. A beloved teacher, Christy mirack, brutally raped and murdered in her home in 1992. Tonight, the cutting edge science that helped finally break open a very cold case. Last spring, the family saw the big news from California. An alleged serial killer tracked down through a genealogy database. The golden state killer. And my first reaction was, why can't they do something like that with Christy? Reporter: Enter cece Moore, a DNA genealogist who started working on cases like Christy's with parabon nanolabs. They upload crime scene DNA profiles to a free genealogy website called gedmatch, and build family trees to find relatives and zero in on potential suspects. A break in Christy's case came in no time. I think it took a couple of days. Reporter: The suspect? Raymond Rowe, also known as dj freeze, a popular fixture in the city for years, charged with criminal homicide. They made an arrest. Reporter: What was that like? It was unbelievable. Reporter: His arrest, one of 11 now credited to this genetic detective. If you're going to commit a violent crime like a rape or murder, you're going to leave DNA behind. And if you leave DNA behind, we can find you. This is incredible. Much more tonight on "20/20." The DNA detective at 10:00 P.M.
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