Warning: This story contains the name and images of a deceased Indigenous person.

Prosecutors say Brearley delivered the fatal blows while he was “hunting for kids” because somebody had smashed his car windows and allege Forth, Palmer and Gilmore helped him, and knew his intent before the incident.

Brearley denies he struck Cassius with a pole, claiming he only punched him after the teen knifed him and that Palmer struck the fatal blows, which he denies.

Palmer told the jury on Monday he waited in his ute near bushland after Brearley ran into it with a pole in a “show of force” to deter a group of young people from coming to Gilmore’s home.

He said he later heard Brearley yelling out for help, saying he had been stabbed, and got out of his car and walked into the bush across a creek towards his voice.

“I can still hear him shouting at somebody  …  asking for the name of the person who gave him the knife,” he said as he recalled the events.

“I keep walking until I come across Jack standing over someone laying on the floor with their arms up.”

Palmer, who previously told the court he was recovering from a serious finger injury that impeded his ability to hold things in his left hand, said the person on the ground was attempting to defend themselves.

He said Brearley was heated and screaming at the “boy” and “it didn’t look like he was going to stop either”.

“I could hear the kid on the floor yelling out ‘I’m sorry, I’m sorry’,” he said.

Palmer said he pushed Brearley away from the person on the ground and said “what the f— are you doing?”

“I seen his head was covered in blood,” he said of the person on the ground.

“Jack made a smart arse comment ‘you’re lucky he came, he saved you’.”

Palmer said the injured boy got up and he asked if he was alright and whether he needed help, but he said he was OK and walked off in the direction of his friends.

He said Brearley was “freaking out” and had two slash wounds to the back of one of his legs.

“He was saying ‘I got to get out of here’, he wanted to leave fast,” he said.

Palmer said he and Brearley later drove to the younger man’s uncle’s home where Brearley discussed fleeing to Broken Hill to “hide out”.

He also said that about three days after Cassius was fatally injured, Brearley and Forth turned up at his home about 2am.

Both were wearing balaclavas and Brearley tried to open the front door before Palmer let them inside, he said.

“That’s when the shotgun came out of the sleeve of Mitchell’s jacket,” he said.

Palmer said the pair paced back and forth in his kitchen and told him they were looking for people connected to the incident on October 13 to “keep them quiet”.

He said he was prevented from leaving his home and he “took it as – if you don’t stay quiet we’ll come for you too”.

Asked by his lawyer, Christian Porter, why he had lied to police in his interviews with detectives, Palmer said he feared what his co-accused would do after the shotgun incident.

He also said he was concerned they might tell investigators about his cannabis-growing operation that Brearley was involved in.

For 24/7 crisis support run by Aboriginal and Torres Strait Islander people, contact 13YARN (13 92 76). Readers seeking support can contact Lifeline on 13 11 14 or beyond blue on 1300 22 4636.