Philomena Dunleavy's son James, 40, is accused of battering her to death before burying her in a woodland clearing on Corstorphine Hill, Edinburgh.
His trial at the High Court in Edinburgh heard yesterday that the 66-year-old, also known as Phyllis, walked into a police station just days before her death asking where she could get a cheap room.
Carole Ross, 50, station assistant at Portobello said the woman she spoke to had "lovely teeth and an Irish accent" She added: "She said her son had had an episode and she walked away from him when he had episodes."
The next morning, April 28 last year, Pc Grant Robertson was on patrol when he was alerted to a woman "in a confused state" on the Western Approach Road.
Pc Robertson said he saw Mrs Dunleavy sitting on an embankment. "She seemed a bit confused and reluctant to engage with me."
Eventually she gave enough information for Pc Robertson and his colleague to take her to her son's flat in Balgreen Road, about a mile away.
It was there, prosecutors allege, that Mrs Dunleavy, from Dublin, could have been murdered between April 30 and May 7. Operation Sandpiper was launched after her near naked torso, severed head and legs, were unearthed on June 7.
James Dunleavy later phoned police to say he thought the dead woman might be his mum. He has pleaded not guilty to murder and attempting to defeat the ends of justice. The trial continues.