One New York judge ruled the DNA evidence was scientifically sound. Another, just miles away, tossed it out as unreliable.
The same scenario is playing out in courthouses around the world amid a debate over whether a type of DNA analysis involving the amplification of tiny amounts of genetic material is reliable enough to convict someone of a crime.
The technique known as low-copy number can be used when investigators collect "touch DNA" samples, a few human cells left behind when someone touches an object such as a gun, the handle of a knife, or even clothing.
While many prosecutors and forensic experts hail it as powerful tool that can help close cases, critics -- most notably the FBI -- argue it is inconclusive and unreliable.
