Lucas Fowler was the adventurous son of one of NSW's most senior police officers.
Chynna Deese was the North Carolina college graduate.
The families of the two young travellers are now in grief after their bodies were found on Monday in the far north of Canada's British Columbia region.
NSW Police have confirmed that the couple was shot dead after their van broke down on the Alaska Highway, 20 kilometres south of Liard Hot Springs.
NSW Assistant Commissioner Mark Jones said they have been told the young couple was shot in "what can only be described as horrific circumstances".
"The RCMP (Royal Canadian Mounted Police) are running this investigation, but our understanding is that they were with a vehicle in the northern part of British Columbia, and it appears they may have been shot in that location," he said.
The injuries inflicted were so "brutal" Ms Deese's heartbroken brother, British Deese, said the family was told a casket would not be allowed at her funeral.
Australian man Lucas Fowler and his American girlfriend were found dead by a Canadian highway. (AAP) Source: AAP
Mr Fowler's father Stephen, the chief inspector for Sydney's north-west Hills district, and other family members have embarked on the long flight to Canada "to be with our boy and to bring him home".
The Royal Canadian Mounted Police are leading the hunt for the killer.
"We recognise this news is troubling for the entire community and absolutely appreciate there are concerns for safety in an area that is popular with nature enthusiasts and tourists," RCMP Sergeant Janelle Shoihet told reporters on Friday.
"This investigation is in its very infancy and it is not yet clear whether Lucas and Chynna were targeted or is this was a crime of opportunity."
NSW Police have sent two homicide detectives to Canada to support the Fowler family, but they will not form part of the RCMP investigative team.
Mr Fowler, 23 and Ms Deese 24, met at a hostel in Croatia two years ago, and on their latest globetrotting escapade packed up an old blue van and set off for a road trip across Canada.
Their bodies were found in a secluded area almost 1900 km, or 21 hours' drive, north of Vancouver, known for the largest natural hot springs in Canada.
"Maybe the van overheated or broke down," Mr Deese told the Charlotte Observer newspaper.
"Something happened on that road, some sort of conflict."
Lucas Fowler, the son of NSW Police Chief Inspector Stephen Fowler, was found dead on the side of the Alaska Highway. Source: NSW Police
One of the last people to speak to the couple were Canadians Sandra and Curtis Broughton, who were driving past, saw the broken down blue van and stopped to help.
Mr Broughton was a mechanic.
"This makes my heart so sad," Ms Broughton wrote on Facebook.
"I can't believe that this young couple are dead now."
Some media reports raise the prospect of a serial killer linked to the Highway of Tears murders, but the freeway where more than 40 people have been murdered or went missing is located 1000 km south of where Mr Fowler and Mr Deese were killed.
The RCMP also distanced itself from the serial killer theory, saying there was no evidence.
"At this point, we have nothing to indicate that their deaths are linked to any other active and ongoing investigations in the area, or if there is a heightened risk to public safety," Sgt Shoihet said.
"I don't think it's a serial killer," Ms Deese's father, Dwayne, told the Observer.
"I think of someone who has been convicted of violent crimes before, someone on drugs.
"What worries us is that person is still on the loose and they have a head start.
"This is going to happen again."
The RCMP released photos of Mr Fowler, Ms Deese and their Chevrolet on Friday and issued a request for witnesses who were on the freeway between 4pm Sunday, July 14, and 8am Monday, July 15, to come forward.
