At the beginning of the month, the FBI began testing out a DNA registry designed to catch sex offenders by matching their genetic profiles to DNA found at crime scenes. The National DNA Index System already contains the genetic profiles of 75-thousand convicted felons and it's being tried out first in Minnesota and seven other states. 36 states already have their own DNA registries, but the national system is intended to help catch offenders who cross state lines. But some concerns remain about the fallibility of DNA matching. We talk to John Sheehy, a defense attorney and partner with Meshbesher and Spence, and prosecutor Steve Redding, Assistant Hennepin County Attorney.