Detectives are still trying to find a potential motive for why a 19-year-old man was murdered in a “furious”, premeditated attack at his home in Adelaide’s west overnight.

The attack, which police believe was intended to kill, allegedly began when the power to the house Carey Avenue in Seaton was switched off just before 10.20pm.

Major Crime Investigation Superintendent Des Bray said that act “lured” Seaton man Scot Phillips outside, where “he was immediately set upon by at least one person”.

Bray said the attacker “unleashed a furious attack on the victim” in his front garden.

“It’s fair to say this was a pre-planned attack,” Bray said.

“The knife was obviously something quite large. We know that from the injuries.

“it was clear from the wounds he suffered it was a deliberate attempt to kill him.”

He said Phillips was stabbed several times, including in the stomach, by at least one attacker, who fled on foot the same way he arrived at the property – south along Fiddock Avenue.

Bray said the alleged attacker had been caught on CCTV and last sighted at Matthews Avenue, but the vision was not clear enough to make an ID.

When fronting media this afternoon, Bray said police had today attended a house in Hectorville and arrested a 19-year-old for possessing a shotgun and ammunition.

He said police believed the Hectorville man “might be a person of interest” in the murder, but that there was no evidence of him being involved.

“We are also pursuing a number of other open lines of investigation.”

Bray said police had not come across a potential motive for the murder.

Phillips was quickly attended to by several people who were in the house during the attack, as well as paramedics, but he died at the scene.

Bray said those people were cooperating with police.

He confirmed Phillips and two friends attended the Seaton Hotel earlier in the evening, but said that was not necessarily related to the attack.

Major Crime officers, crime scene investigators and Western District detectives attended the scene overnight.

Carey Avenue was closed for several hours but has now reopened.

Bray called for anyone in the vicinity of Carey Avenue at the time of the incident, specifically several drivers and a scooter rider caught on CCTV, or anyone with dash-cam or CCTV footage from the area, to contact Crime Stoppers.