Nancy Guthrie Case: Ex-FBI Agent Criticizes 'Mistakes' Made by Pima County Sheriff's Department on Day 1 of the Investigation

A retired FBI agent slammed the "mistakes" made on day one of the investigation six months after Savannah Guthrie's mother, Nancy, disappeared.

Former special agent Maureen O’Connell sat down with Brian Entin Investigates for a Monday, August 10, interview to discuss recent updates in the case.

The Today show host's mother went missing in the early hours of February 1.

As the Pima County Sheriff's Department investigates the idea that the 84-year-old was forcibly removed from her home, Maureen pointed out discrepancies in their examination that may not have been there if the case was immediately handed over to the FBI.

"If it was an FBI case initially, and we saw that she was likely removed from the front of that house but intended to go out the back of the house, those pots would have been gone, the door handles would have probably been gone," she said of potential "mistakes" at the crime scene. "That mat, 100 percent, would have been gone.”

"Our crime scene yellow tape would have been — the street would have been blocked off because we would have been looking for tire impressions and shoe impressions," she added. "Even though the original deputies pulled up because they thought it was a walk-away, as I said, over 90 percent of these cases are."

According to Maureen, deputies' first mistake was failing to shut down the entire block outside of Nancy's Tucson, Ariz., home from the moment she went missing. Instead, the area was swarmed with police, press and amateur investigators.

"The crime scene should've been 15 times bigger than it was," she explained.

Had the FBI been in charge of the case from the jump, Maureen alleged they would have scoped out the entire property "very closely" for potential shoe marks, tire impressions or any other microscopic pieces of evidence.

"Any evidence that people were walking around, any crushed grass below any window on the entire circumference of the residence," she revealed. "You’re looking for any broken glass, which I’m sure the initial deputies did. But this all has to be done by the crime scene team."

"And people should have been directed," Maureen continued. "And I told you, I think early on, when your scene looks like this scene, we’ve talked about how hard it is to collapse a scene. And that’s why you want it bigger initially. You can always make it smaller as you go on, as days go by."

Sources told Page Six that those close to the case are demanding the FBI take over after more than six months have passed with barely any leads.

"Stop the childish finger-pointing," one source said. "There's a killer on the loose. They need to focus their resources on finding that person rather than bickering."

As OK! previously reported, many insiders are "shocked and disturbed" at the lack of updates in a case so far down the line.

Maureen's comments come as Nancy's family renewed their cries to the public for anyone with information to come forward.

"Our family is in agony; we are in a nightmare that will not end. Nothing about our situation has changed," Savannah said in an Instagram video on July 27. "We have done our part. We will never stop looking for her. We will always ache for her and feel that hole in our hearts."

"I'm asking you, begging you to do the right thing now," she addressed her mother's captor. "Make the right choice. Help us find her. Tell us where to look for her. I truly believe it is never too late to do the right thing."