A drag mark could help NSW Police determine if a woman, who was found bleeding and half-naked outside a caravan on a cold morning in the state's central west, met with a tragic accident or something more sinister.
Olivia Hailstone, 38, was found shirtless and unconscious with head injuries outside the caravan she was living in with her partner at Cowra on June 29.
The mother of four was transported to Orange Hospital then to Westmead in Sydney where she is still fighting for life in a critical condition.
NSW Police set up a crime scene and discovered Ms Hailstone was likely attacked on a nearby roadway and dragged back to the caravan.
"There is an indication of a drag mark from a (nearby) roadway to the caravan," Detective Inspector Bruce Grassick told AAP on Friday.
"Part of the investigation will be explaining how she came to be on the roadway. That's still unclear."
Investigators are examining a range of scenarios.
They say Ms Hailstone could have been attacked by an unknown party in a nearby roadway, she may have sustained the head injuries in an accident or she might have been assaulted by her partner.
Det Insp Grassick on Friday confirmed reports Ms Hailstone had phoned her mother the previous night and was upset about an argument she had with her partner.
"It appears (Ms Hailstone) had consumed alcohol, but we're waiting on toxicology results," he said.
Ms Hailstone's partner is co-operating with police.
"We all love her very much," her mother, Jill Twaddell, told News Corp Australia.
"She's got four beautiful children - three girls and boy."