Detective Inspector Tofilau Faa Vaaelua said the police investigation would continue in order to establish the involvement of any one else.
Pairama was a student at Northland College in Kaikohe.
Former principal Jim Luders, who finished at the school at the end of term one, previously told the Herald Pairama was a high-needs student who was very much loved.
"We are absolutely shattered at this news. We put a lot of love and care into her here in Kaikohe.
"She was a high-needs student requiring sensitive support, which she repaid with boundless smiles and energy.
"A very tragic and sad loss.''