Gabby Petito's family sue police for 'failing to recognise' danger signs during traffic stop following row with Brian Laundrie

Gabby Petito talks to police after she and Brian Laundrie were pulled over.  (AP: The Moab Police Department)

The family of American woman Gabby Petito, who is believed to have been killed by her boyfriend, is suing police for "failing to recognise" she was in danger.

The 22-year-old "van life" traveller's body was found weeks after police in Utah stopped her and her boyfriend, Brian Laundrie.

The US$50 million ($71 million) wrongful death suit was announced in Salt Lake City on Monday. 

The pair, who were on a cross-country road trip, were stopped by police on August 12, 2021, in the desert town of Moab, Utah, after they were seen arguing in a grocery store.

Police decided not to press charges but told Mr Laundrie to spend a night at a hotel so the couple had a chance to cool off.

Gabby Petito's mother Nicole Schmidt (top left, in green) wonders if a different police response could have saved her daughter. (AP/Rick Bowmer)

Ms Petito's body was discovered on September 19 on the edge of Wyoming's Grand Teton National Park.

Petito family lawyer James McConkie said officers "failed to recognise the serious danger that she was in, and failed to investigate fully and properly".

Gabby Petito, 22, was a nutritionist and social media influencer who said she loved "art, yoga, and veggies".  (Instagram: @gabspetito)

"They did not have the training that they needed to recognise the clear signs that were evident that morning, that Gabby was a victim and that she was in serious need of immediate help," he said.

An FBI investigation found Mr Laundrie claimed responsibility for her death, before killing himself.

'I wanted to jump in and rescue her'

Police body cam video of the traffic stop showed Ms Petito crying by the side of the road.

She told officers that: 'I just quit my job to travel across the country and I'm trying to start a travel blog … I've been really stressed and he doesn't really believe that I can do any of it."

Speaking at a news conference announcing the lawsuit, her mother Nicole Schmidt questioned whether a different police response may have prevented her daughter's death.

She said watching the footage was "very painful."

"I wanted to jump through the screen and rescue her," she said.

Police officers typically have immunity from lawsuits in many states, including Utah.

Police cam video shows Brian Laundrie talking to an officer, just weeks before his girlfriend's body was found.  (AP: Moab Police Department)

But that immunity was challenged in the wake of high-profile cases including the murder of George Floyd, with the challenges reaching both Congress and the US Supreme Court.

The family's lawyers plan to argue that applying the qualified immunity law to wrongful death claims is unconstitutional and a roadblock to accountability.

A Moab city spokeswoman said the city would not comment on pending litigation.

ABC/wires