A teenager has appeared in court after allegedly shooting his friend dead in a game of Russian roulette while camping in Idaho, US.

Witnesses say Keagan Tennant, 17, and Tim Reeves, 18, pointed firearms at each other while playing the game near Troy on 17 July after a night of alcohol and cannabis use.

Reeves died instantly from a single gunshot wound to the head when Tennant allegedly fired his rifle in his direction.

After the shooting, Tennant was said to have then fired more shots and yelled: "Everyone needs to die; no witnesses."

A witness, identified as Z.W., said he then shouted at the teen: "Keagan stop, you just killed my brother."

Tennant stopped, put the rifle down next to him and started "wailing around" and rocking back and forth, according to court documents seen by KREM-TV news.

The firearms – a .30-06 rifle and a Smith and Wesson .38 revolver – were said to have belonged to the adopted father of Matthew McKetta, who has also appeared in court over the death.

The two accused are alleged to have dumped Reeves' body in nearby woods before going on the run.

The suspects, both from Pullman, appeared in court in Latah Country Wednesday morning (26 July).

Tennant, the son of Pullman Police Commander Chris Tennant, has been charged with a string of offences, including involuntary manslaughter and attempted murder.

McKetta is accused of principal to robbery, principal failure to notify coroner or law enforcement of death, conspiracy to commit failure to notify coroner or law enforcement of death, principal to destruction, alteration or concealment of evidence; and conspiracy to commit destruction, alteration or concealment of evidence.

McKetta is also facing a robbery charge after he allegedly stole a vehicle and $15 from a pizza delivery man in Moscow while on the run.

Reeves was a rising senior at Pullman High School. His family held a memorial for him last week.