A judge blasted a social work report on killer Jay Soso, 20, as “well below the standard” expected by the court.
Lady Dorrian continued the case until next month for better background material to be produced.
Victim Marie Reid, 63, lay dead in her sheltered home for up to four days before her body was discovered, lying in her night clothes.
Before his arrest, Soso - who was 18 at the time - had met her son, Paul, 30, and offered condolences for his mother’s death.
Soso of Home Street, Tollcross, Edinburgh, had faced a murder charge. But a planned trial was halted when he pleaded guilty to a reduced charge of culpable homicide.
He also admitted that he had raped her in her home in Easter Drylaw Way, Edinburgh, in November 2010.
Advocate depute Leanne Cross, prosecuting, told how medics had been unable to determine just how Mrs Reid died - but their suspicions were aroused when they discovered intimate injuries.
Soso was trapped when samples he gave matched DNA found on the body.
Ms Cross told how fishmonger Soso’s mother and Mrs Reid had been good friends when Soso was young. He helped by running errands for her and she treated him, “like a grandson” said the prosecutor.
He was due to be sentenced at the High Court in Edinburgh today.
But Lady Dorrian said the report produced by a social worker had not dealt with the question of what risk Soso poses to the public and appeared to have ignored an account of the facts of the case.