A 12-year-old boy "seemed worried" when he got into a vehicle with a man on the day he disappeared 40 years ago, an inquest has heard.
The West Australian coroner is examining the disappearance and suspected death of James "Jimmy" Patrick Taylor who went missing from Derby, in the Kimberley region, in 1974.
Jimmy's disappearance has remained a mystery, but when a television documentary revealed child killer James Ryan O'Neill had been living in Derby at the time, police looked at the case again.
Michael Gary Griffin told the court on Thursday that he did not know the Taylor family but knew their faces and was sure he had seen a worried Jimmy outside a shop on the day he disappeared.
"He told me he was going somewhere with a white guy," Mr Griffin said.
Jimmy wanted him to look at the man and Mr Griffin warned him not to go if he was concerned.
Mr Griffin said Jimmy insisted he see the man, so he walked to the vehicle.
The man told Jimmy "quite assertively" to get in the car, Mr Griffin said.
"I thought that his tone of voice was unusual," he said.
Mr Griffin declined an invitation to join them and left in his own car before them.
He later heard Jimmy was missing and might have "gone walkabout", Mr Griffin said.
At the time of Jimmy's disappearance, it was suggested he might have run away due to his violent father, who the court heard had a drinking problem.
But Jimmy's brother, David John Taylor, testified he did not think Jimmy was unfairly treated by their father and didn't recall any domestic violence, although his father did use a strap on him.
Jimmy's sister, Sharon Taylor, testified on Thursday that her father taught the family about the importance of education.
"He taught us love of learning, he used to always use phrases like 'listen and learn, pay attention to detail'," Ms Taylor said.
Ms Taylor said they were a close family and she didn't believe her brother had run away.
"I don't see how he could leave us and not return. I don't believe that," she said.
Lionel Gordon Parremore testified via video link from Tasmania that he was 10 years old in 1975 when he got into a car with O'Neill in Tasmania, in between O'Neill abducting and killing two other boys.
Mr Parremore said he reported the incident to police about one-and-a-half weeks later because he could not keep the secret once he learned about one of the other boys.
"I just couldn't live with it anymore," he said.
Mr Parremore said he had to pick O'Neill out of a line-up and touch him.
"You just don't forget that," he said.
O'Neill was never charged over the alleged incident and Mr Parremore did not testify against him.
O'Neill, who was born Leigh Anthony Bridgart, was interviewed by WA detectives in a Tasmanian prison in February 2012, but denied any involvement in Jimmy's disappearance.
The inquest continues.
