Killer identity key to Vic murder case

After fleeing war-torn Cambodia, Ranny Yun was found dead and half-naked on the floor of her suburban Melbourne home in 1987.

The 27-year-old had severe injuries to the back of her head, her throat was slashed and she was naked from the waist down when found at the Springvale house.

Thirty years after her death, Meth Mean is standing trial in the Supreme Court, accused of her murder.

Prosecutors allege Ms Yun was home alone on October 15 when she was killed in the course of a sex attack.

"Whoever killed Ranny Yun definitely intended to kill her," crown prosecutor Nanette Rogers SC told the jury.

"It's the identity of the killer that is the key in this case."

The victim knew Mean through her husband, and was at a Malaysian refugee camp with him before they flew to Australia on the same plane, Dr Rogers said.

Ms Yun's husband Kuy Hieng Thong told the court he and the accused were cousins.

He said he met Ms Yun at a Malaysian refugee camp and they subsequently married.

Mean was extradited from Perth in 2017 after covertly-obtained DNA evidence linked him to the death of Ms Yun.

Semen found on the dead woman's body matched that of Mean.

However, his lawyer argued Mean was not the killer and that the semen was left at the scene following Ms Yun's death.

Two bloody pieces of wood, possibly a broken table leg, were also found hidden under a mattress at the home, the prosecutor said.

Barrister Anthony Lewis suggested Ms Yun's husband either killed her or ordered her death.

Mr Lewis said there was also the issue of Mean's age, as he claims to have been 14 at the time of the killing.

But the prosecution said there was no birth certificate for Mean and witnesses would claim the accused was older.

The trial is scheduled to continue before Justice Jane Dixon on Monday.