BLUE POINT, N.Y. (CBSNewYork) -- The Grand County Sheriff's Department in Utah released the 911 call that a witness made last month that prompted police to pull Brian Laundrie and Gabby Petito over on the highway.
In the bodycam video, police believed Gabby was the aggressor, having left scratches on Brian, but the witness tells 911 Gabby was the one who was hit.
Caller: "The gentleman was slapping the girl."
911 operator: "He was slapping her?"
Caller: "Yes, and then we stopped. They ran up and down the sidewalk. He proceeded to hit her, hopped in the car, and drove off."
The caller then goes on to describe the van the couple was in.
Meanwhile, the FBI searched Laundrie's home Monday in Florida, where he is still missing.
The search warrant document says Petito had many talks and exchanged texts with her mother, Nicole Schmidt, who said that "during these conversations there appeared to be more and more tension between her and Laundrie."
Schmidt also said she received an "odd text" from Gabby on Aug. 27, which reads, "Can you help Stan? I just keep getting his voicemails and missed calls."
Stan is Petito's grandfather, but Schmidt said she never called him Stan. That made her think that something was wrong with her daughter, CBS2's Dick Brennan reported.
WATCH: Ericka Jackson reports from North Port, Florida
As CBS2's Carolyn Gusoff reported, it's a tragic ending that no one in the Long Island town of Blue Point was ready to hear.
Petito was remembered Monday as a beautiful soul, a pure, happy person.
Yet the case is far from over. Another Blue Point native, Laundrie, is still missing. While he is not labeled as a suspect, he is a very wanted man.
In the idyllic waterfront community of Blue Point, there is mourning and grief. A flag is at half staff at the library, where a yearbook shows the smiling images of Petito and Laundrie before their cross country trip became a national mystery, and tragedy.
"It's just so devastating. A beautiful girl, life gone too short," said family friend Denise Chiuchiolo.
"Nobody thought it would end this way. Everybody thought that maybe they would find her alive," said Blue Point resident Giancarlo Biancamano.
"We all feared this would be the ending and hoped for the best, and it's tragic," said Bayport resident Nancy Hill.
Twelve hundred miles away, in North Port, Florida, law enforcement swarmed the Laundrie home, executing a court-authorized search warrant. FBI agents escorted his parents to an unmarked vehicle while they searched.
Laundrie returned to his parents' home from the cross country trip on Sept. 1 without Petito and refused to aid in the investigation in her disappearance. Over the weekend, his parents reported him missing. Days of searching a vast nearby reserve has turned up nothing, begging the question: How did law enforcement lose track of him?
"He was back here in this community for 10 days before she was reported missing. That's a lot of time for someone to get their act together," said Josh Taylor, public information officer for North Port, Florida. "We certainly think Brian has some explaining to do."
Alfredo Garcia, a former Florida prosecutor and dean of St. Thomas University College of Law, explained that before finding a body, there may not be sufficient evidence for constant surveillance.
"They certainly did not have enough to link him to a potential crime, so that tied their hands," Garcia said
The FBI has not said what led them to the Grand Teton location where human remains, believed to be Petito, were found. But it thanked the public for its remarkable response and tips.
CBS News spoke to Petito's close friend, Rose Davis, who said the couple had its issues.
"Every relationship has bumps and everything like that," Davis said. "I would have never have thought this could happen."
Laundrie's attorney had no comment Monday, and a news conference planned for Tuesday on Long Island has been canceled.
An attorney for Petito's family said Sunday's developments were devastating for the family and friends. He wants to give them a period where they can grieve in peace.
The cause of death has not yet been determined.
Petito's grief-stricken father posted on social media, saying that she "touched the world."
"As every parent can imagine, this is an incredibly difficult time," said Charles Jones, supervisory senior resident agent for FBI Denver.
Davis sais she thinks Laundrie has to know something.
"I wanted to text him and be like, please, please give me something," Davis said.
For now, the main focus is on the FBI search and the cause of death of the person believed to be Petito.
Experts say the was body likely exposed to the elements.
"There could be rain, there could be intense heat, insect activity, other animals," criminal pathologist Dr. Priya Banerjee said.
On Tuesday, a coroner is expected to conduct a thorough autopsy.
"You X-ray her. You look at every possible piece of trace evidence, and I don't just mean on the body, but at the scene as well," Banerjee said.
CBS2's John Dias and Dick Brennan contributed to this report.
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