(CNN) Two police officers who responded to a domestic violence call involving Gabby Petito and Brian Laundrie last year in Moab, Utah, should be put on probation for what the city called "several unintentional mistakes" made during the encounter, according to an independent investigator.
Petito and Laundrie were traveling through Moab on August 12 as part of a lengthy road trip when police responded to a call in which a witness said he saw the couple involved in a domestic dispute before driving away.
Officers pulled the couple over after the van exceeded the speed limit, abruptly left its lane and struck a curb, according to a police report.
Body camera video from Officers Eric Pratt and Daniel Robbins shows Petito and Laundrie -- who were engaged -- admitting to having a fight in which Petito said she struck her fiancé first.
During lengthy conversations recorded on the bodycams, Pratt said Petito must be booked into jail since, under the domestic violence statutes of Utah, she is considered the primary aggressor and Laundrie the victim.
Both Petito and Laundrie objected, and the officers eventually agreed not to charge Petito as long as she and Laundrie agreed to spend the night apart.
In the independent investigative report, Capt. Brandon Ratcliffe with the Price City Police Department said the officers neglected their duty by failing to press any charges.
"I believe the officers responded to a domestic violence call and had probable cause an act of domestic violence had been committed," said Ratcliffe. "This should have meant an arrest was made, either by citation or custody."
However, Ratcliffe noted that there appeared to be only sufficient evidence to charge Petito in the matter, not Laundrie.
As part of their vanlife road trip, which was chronicled on social media, Petito and Laundrie later traveled to Grand Teton National Park in Wyoming before Laundrie returned alone to his parents' home in Florida on September 1.
After Petito was reported missing by her family, her remains were found in Wyoming in mid-September. A coroner said she died by strangulation.
Laundrie disappeared just days after Petito was reported missing. He was found dead in a Florida nature reserve October 20 of a self-inflicted gunshot wound to the head.
The FBI described Laundrie as a "person of interest" in Petito's disappearance but an arrest warrant only accused him of illegally using another person's debit card and PIN number and was not tied to her death.
Ratcliffe, who was assigned by the city to review the incident, said he could not speculate on whether different actions by the officers in August could have prevented Petito's death.
"Would Gabby be alive today if this case was handled differently? That is an impossible question to answer despite it being the answer many people want to know," the report says. "Nobody knows and nobody will ever know the answer to that question."
In a statement, the city did not address any potential discipline for the two officers but said it "intends to implement the report's recommendations" on new policies for the police department, including additional domestic violence training and legal training for officers.
"Based on the report's findings, the City of Moab believes our officers showed kindness, respect and empathy in their handling of this incident," the city's statement said.
In an interview for the investigation, Pratt said that while he accepts that he may have made mistakes in conducting the stop, he is still haunted by Petito's death.
"I do care. I am devastated about it," he said. "I cared that day and I still care. I don't think the public gets that we...I don't know if they know we care. I don't know if they know."
Ratcliffe writes in his report that, at the time, neither officer knew his actions were wrong,
"They both believed at the time they were making the right decision based on the totality of the circumstances that were presented," he says.
CNN has reached out to both Pratt and Robbins for a response.