A teenager has admitted stabbing a boy in the back in the midst of a Canberra skatepark fight, but he denies murdering that victim's cousin during the same "quick and confused melee".
The 17-year-old accused pleaded guilty in the ACT Supreme Court on Thursday to a charge of recklessly inflicting grievous bodily harm on a boy aged 16 at the time in question.
He then went on trial, having pleaded not guilty to a charge of murdering the 18-year-old cousin amid the two-minute melee.