A criminology expert says old-fashioned police work and an early million-dollar reward helped locate missing four-year-old Cleo Smith, whose 18-day disappearance broke "all the rules" of a typical child abduction case.
Xanthé Mallett, an associate professor of criminology at the University of Newcastle, said the happy ending to the case was extremely rare.
"Although we all hoped for the best, we were all fearing the worst. Nineteen days is an extraordinarily long time for a child to be missing and to be found safe," she said.
"It's going to be interesting as we go forward … as the police release information to tell us what the motive was … because this does not fit the pattern of a normal child abduction case."
Police have hailed Cleo's discovery as "one of the most remarkable days in policing in Western Australia".
She was found alone in a house in the coastal town of Carnarvon, about 900 kilometres north of Perth.
A 36-year-old man is being questioned by police.
Dr Mallett said police officers faced significant challenges in their search for the girl, with limited technology to rely on due to the remote location.
"This comes down to really good, old-fashioned police work, getting out there in the community and talking to people … but also, the tactic of bringing in that million-dollar reward was integral," she said.
"We wouldn't normally expect that [reward] until maybe years or even decades later.
"That was a very targeted move and a very intelligent move and maybe reflects the fact police have learnt from mistakes in other cases previously… and decided to throw everything at this investigation early on, with amazing results."
Dr Mallett is urging everyone to exercise caution when commenting on the case online.
"Say whatever you like at home but don't post it on social media," she said.
"We've had cases that have been jeopardised by people posting things.
