SA killer 'always a monster', court told

A convicted murderer, who was arrested in Victoria after a DNA match from a discarded coffee cup, has been told he will "always and forever be a monster" to his victim's daughter.

Matthew Donald Tilley, 49, appeared in the South Australian Supreme Court on Thursday for sentencing submissions after being found guilty of the cold case killing of Suzanne Poll in 1993.

Mrs Poll, 36, was found in a pool of blood in the rear of a stationery store where she worked.

She had suffered at least 18 separate wounds, including some that went right through her body.

In a victim impact statement, Mrs Poll's daughter Melissa told Tilley she had so many questions after wondering for 26 years who had "wrecked my whole life".

"But one important one I know I will never get the answer to," she said.

"Why did you kill my mum?

"If it was money, she would have given it to you. You could have taken it and run. You didn't have to make the decision to slaughter her."

Ms Poll said Tilley had lived for the past two-and-a-half decades "free as a bird", all the while knowing how brutally and maliciously he had taken her mother's life.

"I can't think of you as a human the same as me. To me you will always and forever be a monster," she said.

"Society has no place for a monster like you."

At the start of his trial in November last year, prosecutor Carmen Matteo said improvements in DNA techniques ultimately resulted in Tilley being charged.

She said a DNA profile originally extracted from a man's blood at the murder scene returned a familial match with Tilley's brother in late 2017.

That led detectives to travel to Victoria to question the accused and after noticing him discard a disposable coffee cup, they retrieved it and brought it back to Adelaide for testing, ultimately securing the DNA match.

Ms Matteo said an autopsy conducted on Mrs Poll's body found that she died from massive blood loss following the attack in the store.

On the prosecution case, she was killed by a man who entered close to closing time.

In Tilley's defence, his lawyer argued that a key question for the court was whether the evidence had been properly preserved over almost three decades.

On Thursday, the court was told that despite the jury's verdict, he maintained his innocence.

Justice David Peek will impose a non-parole period at a later date.