Investigators may be close to arresting the masked and armed “porch guy,” seen on Nancy Guthrie’s doorbell camera the night she was kidnapped, according to a former FBI agent.

“I think they’re getting close to the porch guy and when they get the porch guy, the floodgates shall swing open,” Former FBI Special Agent Maureen O’Connell told Megyn Kelly on her radio show, leaving the host stunned.

O’Connell, citing her own inside sources, said she was “75%” confident that the haunting figure that has eluded authorities for nearly five months could soon be taken into custody.

“That’s big news. That’s huge — big if true, as the kids say,” Kelly responded, shocked.

Guthrie, the 84-year-old mother of “Today” host Savannah Guthrie, was abducted from her Tucson, Arizona home in the early morning hours of Feb. 1. No suspects have been identified.

Authorities released chilling footage days after her disappearance that showed a masked, pistol-packing man on Guthrie’s porch staring straight into the security camera lens while apparently breaking into the home.

Holding a flashlight in his mouth, he tried to cover the camera with a gloved fist, and then pulled a handful of flowers from Nancy’s garden in an attempt to blot out the lens. He was wearing fleece and a backpack, footage shows.

Investigators have waited so long to make an arrest because they’ve been slowly trying to build a case for when this eventually goes to trial, O’Connell explained to Kelly.

“… From day one, you’re doing your trial prep, practically. Everything you do is geared toward the trial and prosecution,” she said.

“You’re going to have the greatest defense attorney in the world handling this case, whoever takes this case, so you have to operate under the assumption that a couple of big chunks of your evidence may get tossed. So you have to put a case together in such a way that it would withstand losing some of these chunks of evidence,” she said.