An elderly woman accused of murdering her autistic son more than 50 years ago will be released on bail after a Queensland judge labelled evidence against her as "practically non-existent".
Police charged Maureen Anne Enright in October with the murder of Peter John Enright, the fourth of 11 children to Enright and her husband Michael at Inala in south Brisbane.
Peter was born on June 17, 1965, and police believe he died sometime between 1968 and 1969.
The family had been living at the property since 1966.
Despite an exhaustive eight-day search of the home and its surrounds - including digging up the yard and using ground-penetrating radar - the boy's remains have not been found.
During a bail hearing in the Brisbane Supreme Court on Wednesday, Justice Peter Callaghan was highly critical of the prosecution's case.
"You have no effective cause of death, even if you did there is no evidence to sustain an intention to at least do grievous bodily harm," Justice Callaghan told the prosecutor.
"So the charge of murder should not be there, should it?
"It may be many other things, accessory after the fact, maybe manslaughter - but I don't see manslaughter on what you have told me."
Crown prosecutor Mark Whitbread was forced to concede the case was weak but said investigations were ongoing.
"In respect of murder there is no evidence as to what mechanism caused the death of the child, it really comes down to the child just missing from a certain day and the various versions given by Ms Enright as to where the child is," Mr Whitbread said.
Justice Callaghan said the police "had not quite managed to put their case together".
"The applicant faces a case that could be described as weak or in the case of specifically the offence of murder, specifically perhaps non-existent."
Defence solicitor Andrew Bale said his client may have dementia and was struggling to cope in custody.
"The case against the applicant is not strong - it relies on rumour and innuendo," Mr Bale said.
Outside court, Mr Bale said the family was relieved to see that authorities acknowledged there was a complete lack of a crown case against Enright for murder.
"We will be maintaining the pressure that this elderly and unwell lady has no case to answer and should be left alone.
"She has not been coping in custody, and there are real concerns for her mental health."
Family members in court for the bail application declined to speak with media but said they were relieved their mother was coming home.