An Invercargill school has changed its roll-checking procedures after a schoolboy was allegedly abducted by his stepfather.
Mike Zhao-Beckenridge, 11, was picked up during the March 13 lunch break from James Hargest College's junior school in Invercargill by his stepfather, John Beckenridge, in breach of a parenting order.
More than a week after they disappeared in Southland Mr Beckenridge's car was found at the bottom of an 88m cliff near Curio Bay.
Their bodies have not been found.
Yesterday, college principal Andrew Wood said the case had traumatised staff members and led to a change in the way students were monitored.
A "more rigorous" roll check is now conducted immediately after lunch. But Mr Wood says that although such provisions might have highlighted Mike's disappearance sooner, it would not have stopped him leaving, despite the school being made aware of his troubled home life.
The inner-city school wasn't a "fortress or prison" and pupils often left its grounds, especially at lunchtimes.
On the afternoon of March 13, all students were involved in a group "alternative programme" activity, which meant the normal class roll wasn't taken after lunch.
No matter what systems were in place, there would always be occasions when the normal routine was disrupted, Mr Wood said.
"Mike would've known the programme for that day several days in advance so he may possibly have guessed that it was a good day to leave," he said.
Mike had been at the college for only two weeks after moving from Queenstown with his mother, and had kept to himself at school.
Police have referred the case to the coroner but are investigating what they call a missing persons probe.