For crime-scene investigators around the world, information technology is becoming an invaluable tool for cracking tough cases. Whether these crime scenes are virtual or physical, law enforcement is learning to use data-replication devices, specialized search tools, and virtualization software to get the drop on the perpetrators. On the virtual side, it’s all about following the trail of “digital breadcrumbs” left behind by hackers, spammers, and other cybertroublemakers, says Mark Pollitt, president of Digital Evidence Professional Services Inc. and a former chief of the FBI Laboratory’s Computer Analysis Response Team…