Alleged murder victim stabbed repeatedly and left crying for help, jury hears

Father and son Brian and Liam Slann are standing trial accused of murdering 21-year-old William Holdback in April 2024.

Liam Slann has admitted to killing Mr Holdback, but denies it was an act of murder.

The trial before a 14-person jury continues.

A 21-year-old allegedly murdered by a father and son over a disagreement about drugs was allegedly stabbed 10 times and left crying for help on a suburban street, a jury has heard.

Brian Slann, 54, and Liam Slann, 29, are standing trial over the alleged murder of 21-year-old William Holdback in the early hours of April 10, 2024, on a street in Welland in Adelaide's inner north-west.

Both men have pleaded not guilty to murder but Liam Slann has entered a guilty plea to manslaughter, which the prosecution did not accept.

Delivering her opening address in the Supreme Court trial today, prosecutor Nicola Moore said it would be alleged Mr Holdback and Liam Slann had arranged via a messaging app to meet on Musgrave Avenue to purchase or collect drugs.

Ms Moore said Mr Holdback was allegedly trying to source drugs for a friend.

The prosecution alleged Mr Holdback met with the father and son who arrived in a car about 1:20am and there was a disagreement over drugs.

The prosecutor told the jury Mr Holdback allegedly smashed the rear passenger window of the car with a metal bar before sprinting away down Barrpowell Street where he was allegedly chased by Brian Slann and an armed Liam Slann.

"The deceased [Mr Holdback] was first, followed initially by Liam Slann, he was followed in turn by Brian Slann participating in the chase and shouting directions," Ms Moore said.

"The deceased … tripped and he was, the prosecution say, set upon by the first defendant Liam who stabbed him while his father was shouting at him, at his son, to stab him."

"He was stabbed to death and as he lay shouting for help the first defendant [Liam] walked calmly away, not turning around, leaving him to bleed to death, getting into the car with his father and making good their escape."

Ms Moore told the jury the CCTV allegedly had captured Liam Slann saying "I've got you now, I'm going to stab you c***".

"Eight seconds after his son says, 'I'm going to stab you c***,' Brian says, 'Stab him Liam,'" she said.

Ms Moore told the court Liam Slann got back into the car driven by Brian Slann who can allegedly be heard asking his son "where did you stab him?"

She added that a weapon was never recovered, and the pair took a different route home than the one they used to arrive.

Mr Holdback was pronounced dead at the scene, with 10 stab wounds to his chest, shoulder, back of his body and wrists.

Ms Moore said Brian Slann was equally as responsible for Mr Holdback's death as Liam Slann, as the pair had entered a "joint criminal enterprise".

"Liam and Brian came to an understanding, amounting to an agreement by the time they exited the car to attack Holdback with a knife and they intended he should be killed or inflict grievous bodily harm," Ms Moore said.

Defence barrister Nick Healy, for Brian Slann, rejected there was ever an agreement between the pair.

He told the jury there was no dispute that Brian Slann was present on the night and driving the car but was not the principle offender nor was ever in possession of the knife.

Defence barrister Elizabeth Mansfield, acting for Liam Slann, said he admitted his actions caused Mr Holdback's death through his manslaughter plea.

Ms Mansfield told the jury to put aside their feelings of "sympathy" or "distaste" at the confronting nature of the CCTV and come to the evidence with impartiality.