Like a Geiger counter finding radiation, child pornography investigations lead right to the door of humans preying on children where they're least-likely to get caught: in their own daily circles of trust. Here are some of the latest examples:
"At least 350,000 DNA samples from murder and rape cases remain untested," says ProPublica, an investigative news website, and the group is looking at the problem at five forensic crime labs around the U.S.
