Keith Russell Yandle stands trial in Supreme Court accused of murdering ‘defenceless’ man Steven Murphy at Kudla in February 2023

Keith Yandle stood over his victim to watch him die after finding him cowering in his Kudla shed, a court has heard.

A man who found a stranger “cowering” in his cannabis shed shot him once “through the heart”, three more times in the front and back after he fell, then stood over and watched him die, a court has heard.

On Wednesday, a Supreme Court jury heard Keith Russell Yandle watched Steven Murphy “writhe” on the floor after shooting him and, once he had stopped, “stood on his hands” to check he was dead.

Yandle, 48, pleaded not guilty to having murdered Mr Murphy at his Kudla home, outside Gawler, on February 19, 2023.

Yandle instead pleaded guilty to the lesser charge of manslaughter, and to possessing both a firearm and ammunition without a licence.

A Supreme Court jury heard Keith Russell Yandle watched Steven Murphy “writhe” on the floor after shooting him Picture: 7NEWS Adelaide

He also pleaded guilty to destroying human remains to conceal the commission of an offence.

Opening the trial, prosecutor Melissa Wilkinson told jurors Yandle’s manslaughter plea was not accepted, given the events of that night.

Police had, she said, reconstructed video of the incident that had been captured by, then deleted from, Yandle’s own CCTV cameras.

Those “thousands of short files” had, she said, been put back into order to show the final moments of Mr Murphy, who had been “sleeping rough” in the Kudla area prior to his death.

“Yandle entered the shed, armed with a loaded semi-automatic rifle and fired a warning shot to flush Mr Murphy out from his hiding spot,” she said.

Yandle was, she said, joined by his son Marco, 19, who was carrying a torch and armed with a baseball bat.

“At gunpoint and for about 10 minutes, Mr Murphy surrendered to Yandle (who) stood over him as he cowered on his knees with his head down... he was unarmed and compliant,” she said.

“Nevertheless, Yandle shot him four times with the rifle at close range... (the first) shot travelled through his heart... he shot him again as he was on the ground, including once in his back.”

Yandle when checking to see if Murphy was dead “stood on his hands” the Supreme Court heard. Picture: SA Police

Yandle, she said, then sent Marco out of the shed.

“Mr Murphy was writhing on the ground as Yandle watched over him, often aiming his torch and rifle at him... eventually he stopped moving and breathing,” she said.

“A number of minutes passed... after about a half-hour, Yandle appeared to smoke a cigarette as he paced about the shed... he checked the body and stepped on Mr Murphy’s hands, there was no response.”

Ms Wilkinson said Mr Murphy was reported missing on March 18, 2023, and that police twice visited Yandle’s property seeking information.

On April 2, Yandle’s brother, Brock, contacted police saying he had heard “an altercation between his brother and a stranger”.

He said he heard Yandle say “you couldn’t resist temptation” and an unfamiliar voice reply “you’re a dog”, followed by “gunshots and a man screaming”.

Yandle, she said, had told Brock - who has autism - he “fixed up” a “homeless man” who “didn’t matter” and had been “looking for stuff to steal”.

Police searching the property at Kudla. Picture: 7 NEWS

She said police returned to the Yandle property and found the hard drives, a .22 Ruger long rifle modified with a telescopic sight, torch and laser pointer, and 1400 rounds of ammunition.

The gun was, she said, in perfect working order and would fire only if the trigger was pulled - not by accident, or by being bumped or jostled.

They also found Mr Murphy’s remains at the bottom of a 13m by 9m pit dug, in the floor of the shed, by a Bobcat that Yandle had hired.

Ms Wilkinson said Yandle had “alternatives” available to him that night, rather than shooting Mr Murphy, but was unlikely to call police due to his cannabis crop.

“The law recognises the right of someone who’s attacked, or threatened with attack, to use force in self-defence - however, as you might expect, there are limits,” she said.

“There was no need for self-defence... Yandle simply could not have genuinely believed that his conduct, in shooting Mr Murphy multiple times, was necessary and reasonable to defend himself,” she said.

“Yandle intended to kill Mr Murphy - the four shots to the body are evidence of that.”

Bill Boucaut KC, for Yandle, said his client did not dispute shooting nor killing Mr Murphy.

The issues at trial, he said, would be “why” his client “did what he did”, and the CCTV footage itself.

“This is night vision, infra-red vision, from within a very dark shed,” he said.

“Night vision might show all sorts of things that are not visible to the naked eye.”

The trial, before Justice Anne Bampton and a jury of eight women and four men, is expected to run for three weeks.