The Indigenous teenager at the centre of the Northern Territory youth detention scandal had been expelled from primary school for punching pupils and during subsequent jail stints spat at prison staff and defecated and urinated in his cell.

Dylan Voller's​ tragic and chaotic life was spelled out in detail on Thursday as the NT government sought to counter his evidence at the Royal Commission into the Protection and Detention of Children in the NT.

Sonia Brownhill, SC, Solicitor-General and counsel for the NT government, questioned Mr Voller on his statements against evidence from prison guards and his school principal.

She asked him about allegations of erratic behaviour at primary school, of his failure to take the ADHD drug Ritalin, of hitting students in the playground, of often being escorted to the school "time out" room where he smashed a louvre window, defecated on the floor and tied socks around his neck.