It could be just one phone call or piece of evidence that makes the difference to the Moira Anderson investigation.
Police say they are determined to find her remains, which could finally conclude that Alexander Gartshore was responsible for the 11-year-old’s death.
Prosecutors are so convinced he is the killer that in 2014 they issued a statement saying that, if he had still been alive, he would have been indicted for Moira’s abduction and murder.
Detective Superintendent Suzie Chow, who heads Police Scotland’s Homicide Governance and Review – cold case – unit, says it “remains a live investigation.”
She said: “I would appeal to the public for any information which will assist with recovering Moira’s remains.
"Any new information or intelligence which is passed to police will be assessed and investigated thoroughly.”
No body has been found despite a search which has seen a canal dredged and graveyard inspected.
In January 2013 investigators excavated the plot of Sinclair Upton, said to have been an acquaintance of Gartshore, to see if the schoolgirl’s remains were hidden there.
The excavation at Old Monkland Cemetery in Coatbridge was led by Professor Sue Black and a team from the forensic anthropology department at Dundee University. It was unsucessful.
It seemed the case would finally be solved when Sandra Brown came forward in the early 90s and connected her father, bus driver Alexander Gartshore, to her disappearance.
One witness said they had seen a bus similar to the one Moira boarded on a country lane. The lights were off.
Another claimed to have seen a man dragging a girl by the arms near the Carnbroe bus terminus that day.
The witness later identified the man as Gartshore.
Don't miss the latest news from around Scotland and beyond - Sign up to our daily newsletter here .
