Nancy Grace Weighs in on Gabby Petito Case and Brian Laundrie's Family's Legal Culpability (Exclusive)

ET spoke with the legal commentator about Petito's case and what the next steps are.

Nancy Grace is weighing in on Gabby Petito's case and Brian Laundrie's whereabouts.

The legal commentator spoke with ET about the latest developments in the 22-year-old vlogger's tragic death as the manhunt for her fiancé continues. She also touched on Laundrie's family's legal culpability in the case and what the next steps are.

"Many people are pointing the finger at Brian Laundrie's parents just like Gabby's family is," the host of America’s Most Wanted Overtime on FOX Nation told ET, noting the information about Laundrie's actions, including his return to Florida without Petito and allegedly using her debit card. "He gets all the way home to Mommy and Daddy in Gabby's van. And despite Gabby's parents calling and calling, texting, emailing, they won't take the calls. They won't tell Gabby's family she's not there and that she's missing. This goes on for days and days. And in the last hours, we learn that they have completely blown up the FBI timeline."

Petito's remains were found late last month after she had gone missing while on a cross-country road trip with Laundrie. A federal arrest warrant was issued for Laundrie after he was named a person of interest in the Petito case. On Sept. 17, an attorney for his family contacted the FBI and said they had not seen him since Sept. 14. Petito's family recently sat down with Dr. Phil, recalling how they reached out to Laundrie's family after their daughter went missing.

"After they are confronted by the FBI, they admit that Brian Laundrie actually left one day earlier for the Carlton Reserve," Grace said. "That gives him another day's head start. He has now ghosted us for 23 days and counting."

As for whether Laundrie's parents can be subject to an arrest, Grace believes they can be if they lied.

"Many legal eagles have been speculating as to whether Brian Laundrie's parents can be charged with a crime," the journalist said. "Here's the deal, under our jurisprudence you don't have to be a hero, you don't have to go to cops and tell them what you saw or tell them what you know. You don't have to save someone from a crime, you don't have to do anything. You're not compelled to tell the truth to police."

"However, if you do speak to police, and they have, if you lie, that is a crime," she stressed. "Now, interesting under Florida law, family members, when it comes to for instance a third degree felony or lower, are somewhat exempt from accomplice after the fact. You can give food, money, sustenance, blankets to your son or daughter. But what you can't do is lie to law enforcement or help in a crime. So if they have remained silent and not misled law enforcement, they may escape criminal liability."

Grace added that as of now, Laudrie's parents are alleging, "'The FBI jogged our memories. Now we remember the last time we saw our son. It was the day before.'"

"I find that very hard to believe because I can remember precisely the last time I saw my son or daughter," Grace said. "And when you're telling the cops you think your son has gone out into the wilderness and is going to commit suicide? You'd think the parents would remember the last time they talked to him!"

Grace suggested that Laundrie's parent's change in their timeline "is so critical." "It totally blows up what the cops in North Port, in Sarasota County, the sheriffs that the FBI had been trying to track down. Video surveillance, the toll booths on ring cameras, on credit card receipts, tracking for a particular day, that's all down the tubes," Grace noted. "They have to restart with a new timeline. That's a big deal. Many people have asked me what should Laundrie's parents be doing right now. I think Laundrie's parents need to be telling the truth."

Meanwhile, Duane "Dog the Bounty Hunter" Chapman has joined in on the search, and Grace said that any leads will be helpful when it comes to discovering what really happened to Petito.

"A lot of people poo poo Dog the Bounty Hunter. But you know what, if we get tips and leads about where Brian Laundrie is and what happened to Gabby, who cares where it comes from," she expressed. "He has also brought a lot of much-needed attention to Gabby Petito and Brian Laundrie, which increases public awareness. What does that translate to? It's more likely someone will spot Laundrie now that Dog is in the fight."

Last month, Petito's family held a public memorial service for their daughter. Her remains are still with the medical examiner. A cause of death has yet to be announced.

"Another very important fact, once a cause of death is announced, that means much of the medical examiner's investigation is over," Grace noted. "When that is done, all that evidence becomes subject to FOIA, Freedom of Information Act. I believe the FBI in particular want to play their cards close to the vest and not release any information they don't have to until the time is right."

For more on Petito's case, see below.