The trial of two teenagers charged with the brutal murder of a service station attendant in Queanbeyan has been abandoned, after the second of them pleaded guilty in the New South Wales Supreme Court on Monday.

Key points: Teenagers accused of a rampage through Queanbeyan have both pleaded guilty to murder

Teenagers accused of a rampage through Queanbeyan have both pleaded guilty to murder 29-year-old Zeeshan Akbar was found dead on a service station floor after the 2017 rampage

29-year-old Zeeshan Akbar was found dead on a service station floor after the 2017 rampage The pair have also admitted to other acts of violence, including a second stabbing.

The pair's rampage in April 2017 left service station worker Zeeshan Akbar dead, and another man on the kerbside with stab wounds.

Mr Akbar, who was 29-years-old when he died, was found on the shop floor with multiple stab wounds by a co-worker arriving for his shift.

The killers, who cannot be named for legal reasons, were only 15 and 16 at the time.

They were caught across the border in the ACT after a police chase in a stolen car, but were extradited back to New South Wales a day later.

Victim's parents travel from Pakistan to witness trial

Both teenagers have pleaded guilty to the 2017 murder at the Queanbeyan service station. ( ABC News: Elise Scott )

Legal proceedings have been protracted, with the trial delayed several times before being abandoned altogether today.

The younger of the two accused pleaded guilty last week. On Monday, Mr Akbar's parents and several siblings watched on as his co-accused also admitted to the crime.

They had travelled to Sydney from Pakistan, and were too distressed to talk as they left court.

The 19-year-old pleaded guilty to murder, robbery, and stabbing another man and stealing his car.

But the matter is not done yet, with Justice Geoffrey Bellew, setting a time table for parties in the case to agree on a set of facts.

Previously, dramatic CCTV footage of the attack was viewed by a court during a failed bail application by one of the accused.

The two are expected to be sentenced next month.