Murderer "felt the presence of the devil"

The unmarried Leyton pensioner died of severe head injuries and pneumonia a week after the attack in Lea Bridge Road in June 1994. Ross was arrested for the murder last year after his palm-prints were matched to bloody marks above the murdered woman's bed. He had been arrested after smashing a restaurant window following a row over the price of a pizza.

In passing sentence, Judge Gerald Gordon said: ""Helen Mercer was clearly very vulnerable. This was to all normal people a repulsive attack and it took place in her own room."

The court heard Ross, 39, had suffered from a history of drug-related psychosis, and had told psychiatrists he had often "heard voices talking about him".

Following the death of his father in 1990 from lung cancer, Ross had begun abusing alcohol, cannabis and cocaine. He had cut his wrists with a broken cup in front of his brother in 1990, and by 1995 had become convinced his girlfriend's ectopic pregnancy "was the result of witchcraft".

He had been admitted to a psychiatric hospital in 1998, and was subseqently treated at the Royal London Hospital in 2001, 2006 and 2007.

Ross also had two minor convictions for assault before the murder.

Judge Gordon said: "Much remains unexplained, in particular why you were there at all and also why - whether alone or with others - you chose to attack her in the way she was attacked."

Ross' sentence will take into account the 321 days he spent in custody following his arrest in August last year.

Read The Wharf's exclusive coverage of the two-week trial here, here and here.