Missing person files across Australia are being checked and police will trawl through the background of a man charged over an attack on two backpackers in South Australia to unearth any possible links to other crimes.
A special task force is investigating the attack and police are also fast-tracking the processing of DNA samples taken from the 59-year-old Adelaide man who is in custody.
"The very nature of this incident cries out to inquire into the background of this particular suspect," Acting Assistant Commissioner Doug Barr said on Friday.
"We will be trawling through his history and other persons he may have come across in the course of the last few years."
Asst Comm Barr said every outstanding missing persons case would be checked.
"These sort of cases are very rare, they don't occur very often," he said.
"When they do happen they are a trigger to us to enquire into what has gone on in the past that we haven't known about."
Two women in their 20s were attacked at a remote campsite at Salt Creek in the Coorong National Park on Tuesday with one allegedly sexually assaulted.
A Brazilian woman has since been released from hospital while her German companion remains under care with serious head injuries and is yet to talk with investigators.
She was left covered in blood after the alleged attack and witnesses have described the shocking scenes as she was rescued by fishermen after fleeing from a beachside camping ground.
"It was horrific. It was like something from a movie. It was Storm Boy turned into Wolf Creek," another, unrelated, camper Josh Harris told AAP.
"At first I thought it was mud on her face. As she walked, supported by people, blood was all over her."
Asst Comm Barr said the woman had been subject to a terrifying incident that had shocked police and the wider community.
"It's a horrific thing for any victim to go through," he said.
He also confirmed that police would return to Salt Creek in the coming days and were prepared to conduct a major search if necessary.
