Finally, there's been a huge new development in the search for Nancy Guthrie. ABC News sources revealed on Thursday that the FBI has received and is now analyzing very, very key DNA evidence found in the 84-year-old's home. And while the evidence isn't brand new, the fact that the FBI now has control of it could be huge! Here's the deal. The DNA sample was first sent to a private lab in Florida, which the Pima County Sheriff's Department uses. But in recent weeks, according to the sources, that lab sent the sample to the FBI, which had been eagerly awaiting its chance to get involved.