Nearby residents rushed to the school, alerted by the sound of gunshots. Higgins barricaded himself in the headmaster's office, brandishing his revolver at the approaching men. Not knowing how many and what types of weapons Higgins might be carrying, they were forced to retreat from the school and wait for reinforcements. Sergeant O'Grady and Constable Herbert Olsen soon arrived from Waihi, six kilometres away, along with several of Waikino's best marksmen.
Higgins exchanged shots with the officers over several hours, severely wounding Constable Olsen. Eventually, Higgins threw his revolver out the window and gave himself up. On examining the schoolhouse, police were surprised to find there were still bullets left, as well as a crude gelignite bomb. They were even more surprised to discover that headmaster Reid, shot twice and left bleeding during the lengthy siege, was alive and conscious. He had lain silent and motionless for hours, hoping that Higgins would not notice that he was still alive.
Two boys - Kelvyn McLean, 13, and Charles Stewart, 9 - were killed in the attack, and several other children suffered serious injuries.
As word of the incident spread, so did speculation about Higgins and what might have motivated him.
Higgins was known as a loner and something of an eccentric, but no one had imagined he was capable of violence on this scale. When questioned by police, Higgins claimed he couldn't remember why he had gone to the school, or what he and the headmaster had argued about before the shooting.
It was a week before Robert Reid was well enough to make a police statement. He described Higgins complaining of being persecuted by neighbours, insisting that one of them had killed his horse.
Higgins had settled in bushland near Waikino some 16 years before, building a log cabin on his isolated 20ha property. He had grown convinced that neighbours were spying on and sabotaging his property, killing his chickens, moving fence posts and stealing bees from his hives. Higgins told Reid he planned to "wipe up" his neighbours' children in retaliation.
Pupil Kathleen McGarry had seen Higgins on her way to school that morning, when he had asked after her parents and offered to give her a ride on his cart. Hours later, he shot her in the leg as she sat at her desk. Kelvyn McLean recognised the assailant and approached him, pleading "You won't shoot me, will you, Mr Higgins? Remember I used to help you fill your firewood sacks." Higgins shot the boy at point-blank range.
The defence at Higgins' murder trial didn't dispute the events at Waikino School but pleaded insanity, and the trial was delayed repeatedly as both prosecution and defence gathered expert witnesses to testify to Higgins' mental state at the time of the shooting. In total, eight doctors were called to give evidence at the Supreme Court trial.
The first, Dr S.A. Bull, examined Higgins for an hour and deemed his lack of remorse and emotion unusual, because "as a rule Irishmen were emotional", and deemed it likely that Higgins' persecution complex had led him to "homicidal mania".
The Crown presented four experts who gave the opinion that while undoubtedly suffering paranoid delusions, Higgins was still able to recognise that his actions were unconscionable, and argued that the home-made bomb was proof that the massacre at the school was a deliberate, planned act.
The jury took just an hour to return a guilty verdict on the two charges of murder, although Parliament exercised its prerogative of mercy to commute Higgins' death sentence to life imprisonment. He remained incarcerated until his death in August 1937.
The funeral of the two slain boys was one of the largest the Waihi district had seen.
As for the survivors of Higgins' rampage, Constable Olsen recovered and returned to police duties seven months after the shooting, while headmaster Robert Reid was unable to return to teaching and received an early pension from the Department of Education.
The Cabinet approved £50 payments towards the medical expenses of three children seriously injured in the attack. Higgins' family found themselves unwelcome in the close-knit Waikino community, and so local residents and Truth readers raised almost £100 to allow Higgins' wife to return to her native Canada with their two children.