FBI Close to Finding Masked Suspect From Nancy Guthrie Kidnapping, Former Agent Claims

It sounds like a big break is imminent in the Nancy Guthrie kidnapping case ... a former FBI agent says the feds are closing in on capturing the masked suspect caught on video outside Nancy's front door.

Former FBI Special Agent Maureen O'Connell was on "The Megyn Kelly Show" and she said she is 75% confident the masked suspect will be tracked down.

Check out the clip ... Maureen says the floodgates will really open once law enforcement finds the perp.

The FBI's been looking for the masked suspect for a couple months now ... they were seen on Nancy Guthrie's Nest Camera on February 1st -- around the same time she was abducted from her home in the middle of the night.

There's a lot of conspiracy theories about who is behind the mask ... and their clothing, backpack and gear provide some clues.

As we told you ... we recently got in touch with an FBI source who is directly involved in the kidnapping investigation ... and they told us about the ransom demands and the person claiming they know where Nancy's buried.