Today marks 15 years since the murder of Peter Falconio — and the incredible escape of his girlfriend Joannes Lees, who ran into the bush away from would-be kidnapper Bradley Murdoch.

The remarkable bravery shown by Joanne Lees in escaping from Murdoch and hiding in nearby bushland led some people to initially question her version of events on that fateful night.

But Colleen Gwynne, who was promoted to be in charge of the Alice Springs region during the investigation, said she never doubted Joanne’s story.

“I knew straight away she was an incredibly credible witness,” she said.

“Her recollection of the event of July the 14 was incredible – her attention to detail was second to none.”

She came over to England to meet Joanne in Brighton and tell her that Murdoch had been arrested.

She then travelled to Hepworth to meet Peter’s parents to tell them the police knew who had killed their son and that they were determined to convict him.

Peter Falconio and Joanne Lees on their holiday in Australia

When the unanimous guilty verdict was brought back in at the end of Murdoch’s trial, she said Mr Falconio’s mother Joan “turned and mouthed ‘thank you’ to me”.

The verdict means just one question now remains from a case which at the outset was riddled with them.

And that is where Murdoch disposed of Peter’s body.

It is a question which Ms Gwynne fears may never be answered.

The murder of Peter Falconio: A timeline