The final year and awful death of Gisborne schoolgirl Reiha McLelland

Back has since been struck from the Register of Teachers. His partner Angie Mepham, also a teacher, was complicit in Back's misjudgment yet escaped with a caution.

But the path to Reiha's final days involved others.

There were the mental health professionals who saw her; the police called to investigate her relationship with Back; the senior detective who was managing the officer who carried out the investigation while chairing Back's school's board of trustees. There was also Gisborne Intermediate, which didn't fire Back after it learned of the relationship.

"We're learning a lot of stuff backwards," says Hinemoa.