LONG ISLAND, N.Y. – The attorney for now-deceased Brian Laundrie and his vilified parents said he has been told by the FBI that they believe they "have everything they need" with respect to the investigation into the murder of Gabby Petito. 

Sitting down with Fox News Digital at his New York office Friday, Steven Bertolino addressed questions about whether Chris and Roberta Laundrie planned to cooperate in the investigation into the death of their son's late fiancée. After explaining what the FBI had told him, Bertolino added: "I was unaware of that as of yesterday. So, things change every day in this saga."

"And it is tragic. It's very sad," he continued. "So, ultimately, we'll see that through as it needs to be."

The FBI declined to comment when Fox News Digital sought confirmation on this revelation.

Bertolino contends his clients cooperated with investigators when it came to the search for their fugitive son. But the Laundries have otherwise stayed mum in relation to Petito’s homicide, for which the FBI has said their son was a person of interest

Petito, 22 and Laundrie, 23, had embarked on a cross-country trip in mid-June with the plans to sightsee and visit national parks in a white Ford Transit. 

Gabby Petito, left, and Brian Laundrie are seen in bodycam footage released by the Moab City Police Department in Utah. (Moab City Police Department)

According to law enforcement records, they got into a physical altercation during their stay in Moab, Utah, on Aug. 12, which led to a police stop for a possible domestic violence case.

Police closed out the call without filing any charges or issuing citations, but officers ordered Laundrie and Petito to spend the night apart. Officials are now investigating if the officers’ handling of the case violated Utah law.

On Sept. 1, months after the couple began their trip, Laundrie returned to the North Port, Florida, home in the van, but without Petito, officials said. The young woman was not reported missing until 10 days later, on Sept. 11, when her mother filed a police report in New York. Police seized the van from the Laundries' home that same day. 

BRIAN LAUNDRIE WAS 'GRIEVING' WHEN HE VANISHED, DAYS BEFORE GABBY PETITO FOUND DEAD: LAWYER

Petito’s relatives said they repeatedly tried reaching Laundrie and his parents when they grew nervous about their daughter’s wellbeing, but the messages went unanswered. 

On Friday, Bertolino said he spoke to Brian Laundrie on Sept. 12 and Sept. 13, the same day he is alleged to have disappeared after leaving for a hike in the nearby Myakkahatchee Creek Environmental Park. 

The attorney, who said he has known the Laundrie family for more than 20 years, said during a previous television interview that Brian was "grieving" and was upset when he left for the hike that day.

On Friday, he stepped away from that, saying he used the "wrong term," and "could have used a better choice of words." 

"I still stand by that Brian was upset, he was distressed. … He was out of sorts," Bertolino told Fox News Digital. "At the time, Chris said, you know, ‘I couldn’t stop him. He was going.’ Brian was determined to go for a hike, and that seems to be something that we wish he didn’t do." 

I still stand by that Brian was upset, he was distressed … he was out of sorts.

— Steven Bertolino, Laundrie family attorney

He would not explain why Brian Laundrie was so upset that day, citing confidentiality concerns. 

BRIAN LAUNDRIE SEARCH: NO DISCREPANCY BETWEEN FBI AND PARENTS ON MISSING TIMELINE, SAYS FAMILY LAWYER

Brian Laundrie (Instagram)

Brian Laundrie (Instagram)

"There was a lot going on. They were getting phone calls over the weekend. You know, Gabby was missing," Bertolino said. "He needed to get out and clear his head." 

Bertolino, who had initially identified the date of Brian's disappearance as Sept. 14 before changing the timeline weeks later, stands by his revelation earlier this week that he did notify the FBI on Sept. 13, the day Laundrie left for the hike. 

BRIAN LAUNDRIE SEARCH: FAMILY LAWYER ADDRESSES RUMORS PARENTS PLANTED EVIDENCE IN FLORIDA SWAMP

He previously attributed the confusion over when Brian was reported missing to authorities to a lack of communication between himself and law enforcement agencies. 

After initially notifying the FBI on that Monday that Brian had not returned, "there was never any communication between myself and law enforcement in the next three days," he said on Thursday.

When asked on Friday why neither he nor the parents followed up with authorities about Brian’s whereabouts, he said, "Blame could go on either side." He added that he, the North Port Police Department and the FBI had since "cleared the air." 

Police outside Brian Laundrie's house on Saturday morning (Maciel/Backgrid)

"In my words, I never called the FBI on Tuesday or Wednesday or Thursday, and the FBI never called me on Tuesday, on Wednesday or Thursday," he went on. "We had our reasons for not calling them, and they perhaps had their reasons for not calling us."

When it came to officially filing a missing persons report for Brian, Bertolino said he went as far as getting an outside opinion as to whether or not he would be violating attorney-client confidentiality by doing so. 

"I had to get an ethical opinion on Thursday the 16th, just to make sure that if I were going to report Brian missing that I wouldn’t be violating any privileges or confidences that my client had," he said. "I am confident in what I did in my role here — the parents were aware of it every step of the way."

The FBI’s Denver Field Office announced in a statement Thursday that Laundrie was positively identified using dental records as being those found within the Myakkahatchee Creek Environmental Park on Wednesday morning. 

That same morning, Chris and Roberta Laundrie searched the park, which is attached to the T. Mabry Carlton Jr. Memorial Reserve, with the assistance of two law enforcement officers. 

GABBY PETITO HOMICIDE: TIMELINE OF DISAPPEARANCE WITH BRIAN LAUNDRIE

Laundrie’s remains and some of his belongings, including a notebook and a backpack, were found on or near a trail that he was known to frequent, said authorities and the attorney. In announcing the discovery on Wednesday, Michael McPherson, special agent in charge of the FBI Denver, said the remains and the items were found in an area that had been underwater until recently.

After a weeks-long search of the Florida swamp left authorities with no answers, the park was reopened to the public Tuesday. The Laundries then notified authorities they wanted to search Brian's frequented spots, Bertolino said at the time. 

During the couple's time inside the park, a Fox News Digital reporter witnessed Chris and Roberta Laundrie search the area with two law enforcement officers. 

The images show Gabby Petito in her sophomore year and Brian Laundrie as a junior at Bayport-Blue Point High School in New York.

During their search, the Laundries discovered a white bag and a dark-colored object after traveling through a patch of brambles at the edge of the brush at a clearing. They then could be seen putting the object into the bag and handing it over to the law enforcement officer shortly thereafter.

In video obtained exclusively by Fox News Digital, the Laundries and the law enforcement officer are seen huddling and speaking as the officer appears to show the couple another discovered object. The officer appeared to tell the parents: "I think we might have found something." The officer could be seen patting Chris Laundrie's shoulder as he huddled with them.

The now-deceased couple met years earlier on Long Island, New York, where they grew up, and later moved into the Florida home with Brian’s parents.

Petito’s body was discovered in Wyoming on Sept. 19. Investigators have ruled her death a homicide and found she died of manual strangulation. 

Fox News' Michael Ruiz contributed to this report.