Gruesome allegations have emerged that a man murdered his housemate, then set fire to her body in an attempt to destroy evidence, a South Australian jury has been told.

Krystal Marshall’s charred remains were found face down on her bed in October 2023 at her Aldinga beach home, in Adelaide’s south.

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Her housemate, Johnathan Paul Parker, 51, is standing trial in the South Australian Supreme Court. He has pleaded not guilty to murder but guilty to destroying human remains to pervert the course of justice.

Prosecutor Jim Pearce KC told the court Parker had strangled Marshall before setting her body alight.

“He had a problem on his hands — a dead body in the front bedroom of the house,” Pearce said.

“The next day he set fire to Ms Marshall’s body in order to destroy the evidence.”

Johnathan Parker is accused of killing Krystal Marshall Credit: 7NEWS

The court heard Parker locked the bedroom door, spread petrol throughout the home, placed furniture in the hallway and lit five separate fires inside the property.

A post‑mortem determined Marshall was dead before the fire started.

Pearce told the jury Parker had allegedly confessed to killing Marshall, telling a friend he “grabbed her around the throat and squeezed, and when he let go, she fell face first onto the bed”.

The court heard Marshall had wanted Parker out of the house, and that the issue “may have been a catalyst for her death.”

Police body‑cam footage played to the court showed officers arriving to panic and chaos on the day of the blaze — and Parker insisting he had “no idea” where Marshall was.

The trial continues.