Jury views pictures of blade attack

Beach attack: Police at Wedge Island. Picture: Bill Hatto/The West Australian

Chilling mobile phone footage of an alleged machete killer taken moments after a New Year's Eve partygoer was hacked to death on a WA beach has been shown to a Supreme Court jury.

Joseph Robert Houston has denied murdering James Dorloff, who died on the sand at Wedge Island after his jugular vein was severed in the first hours of 2014.

Mr Houston is also accused of causing grievous bodily harm to another partygoer Tyson Cumming, who told the court how he was attacked after remonstrating with Mr Houston.

The graphic footage of the incident shows Mr Cumming approach Mr Houston then quickly back away, holding his hand.

The video then shows what prosecutors say is Mr Houston stalking the beach with what appears to be a big knife in his hand.

Mr Cumming, 26, said having heard screams and then seen Mr Dorloff lying on the sand, others on the crowded beach indicated Mr Houston was responsible.

"I thought he was going to walk off and my instant reaction was to keep the bloke here until the cops came," Mr Cumming said.

"He took that the wrong way and decided to take me."

Mr Cumming said he put his hand up to protect his face from the swinging blade and sustained serious injuries.

"My hand went numb, and I decided to get out of there," Mr Cumming said.

After being flown to Perth for emergency treatment, Mr Cumming had four severed fingers reattached. He also had nerve and tendon damage.

Despite microsurgery, he said his hand was still not back to 100 per cent capacity.

Prosecutor Justin Whalley earlier said Mr Houston set out for the New Year celebrations with the machete and yelled, "Who wants to get stabbed", as he swung the blade.

He then fled into sand dunes and buried his shirt and the machete, prosecutors said.

Defence lawyer Anthony Eyers said issues of self-defence and defence of another would be raised during the trial.