(NBC News) — Witnesses are beginning to provide pieces of the puzzle as investigators search for clues in the disappearance of North Port woman Gabby Petito.

Petito, 22, left New York to embark on a cross-country trip with her fiancé, Brian Laundrie, 23. She last contacted her family around the end of August, when the couple was visiting Wyoming’s Grand Teton National Park.

On Thursday, police in Moab, Utah, released body camera video showing officers pull over their van at Arches National Park after a witness reported seeing them arguing and hitting each other. The video shows Petito trying to explain what sparked the argument and Laundrie talk to police. The couple agreed to give each other space and spend the night apart. No arrests were made.

Laundrie returned to their North Port, Florida home without Petito on Sept. 1. He is considered a person of interest in the case, according to police.

Now authorities in Wyoming are searching Grand Teton National Park, the last place she was seen.

Shannon Baker said she spotted the couple’s van on Aug. 25 and contacted police.

“It had the black ladder on the back and the two black rooftops on top—the two bars—and we made the comment that would be the perfect little camper van to go around in,” Baker said.

Investigators are hoping more people come forward with information regarding the case.

“You never know what you’ve got in a photo,” said Teton County Sheriff’s Office Sgt. Clayton Platt. “Low and behold there was a van that matches the description of this van in this case. All those little pieces can be pieces in the puzzle to help us figure out where Gabby is.”

Multiple agencies, including the FBI, local police and the National Park Service are working together to aid in the investigation.