Pictures of anguished parents running through the streets for news of their children deepened public outrage, and a crusade to tighten controls — led by townspeople and victims’ families — won widespread support.
The "Snowdrop Campaign," which took its name from the only spring flower in bloom at the time of the massacre, resulted in a ban on all private hand-guns.
That response contrasts with the inertia surrounding efforts to tighten gun controls in the United States, where public opinion remains much more divided on whether such changes are necessary.
It puzzles some of the Dunblane families, for whom shootings such as the 2012 Sandy Hook massacre in Connecticut bring back painful memories.
“You feel how they feel and we got something done about it, whereas for families in America there is still suffering,” said Alison Ross, 20, whose older sister was among the victims and whose mother Pam helped organize the Snowdrop Campaign.
“You understand their want for something to be done because that is how we felt as well,” she told NBC’s U.K. partner, ITV News. “Something had to change, and it did change.”
Mick North, whose daughter Sophie was killed in the March 13, 1996 massacre, believes the changes made Britain a safer place.
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“School and college shootings occur with sickening regularity in the U.S., yet too many politicians claim that everything but gun ownership is responsible,” he told the Radio Times this week. “Their blinkered and uncritical support of gun rights means that the problem will never go away.”
He said parallels have been drawn between the shootings at Dunblane and Sandy Hook — but there's a critical difference.
"The horror at the mass killing of children and teachers, the sympathy for their families, were the same as we’d experienced. The legacy was not,” he said.
In 2015 the U.S. saw more mass shootings — defined as incidents in which four or more victims are shot — than days in the calendar year. Yet there is almost no demand for curbs on gun ownership such as the one imposed in Britain after Dunblane.
Obama's initiative also calls for hiring hundreds of examiners to help the FBI do the increased background checks — roughly 22.2 million were conducted in 2015 — and it requires weapons merchants to notify the Bureau of Alcohol, Tobacco, Firearms and Explosives if their guns are lost or stolen.
Even these modest changes have encountered strong opposition, most notably from the National Rifle Association which said in January that none of the changes would have prevented any of the shooting tragedies that Obama cited at a tearful news conference unveiling the initiative.
“The timing of this announcement, in the eighth and final year of his presidency, demonstrates not only political exploitation but a fundamental lack of seriousness,” the NRA said.
It is true that Britain’s handgun ban failed to prevent another mass shooting. In 2010, a taxi driver shot dead 12 people in a killing spree in Cumbria, northwest England. It later emerged that the driver held a valid shotgun certificate as well as a longstanding firearms license for pest control and clay pigeon shooting.
Overall, firearm offences involving any type of injury have declined since the 1996 handgun ban, falling to 1,340 last year compared to more than 5,000 only a decade ago. There were 19 deaths from crimes involving guns in 2014-15, the lowest recorded figure in a quarter of a century, according to the Home Office, whose figures cover England and Wales. However, outlawed handguns accounted for 11 of those 19 deaths.
The majority of police in England and Wales are unarmed — reflecting lower levels of violence aimed at police officers — and officers discharged their guns just twice in 2015 out of more than 14,000 firearms operations. And the most common weapon used in violent crime in Britain is not a gun, but a knife.
The Dunblane shooter, unemployed 43-year-old Thomas Hamilton, was the legal owner of all four handguns used in the attack: two Browning pistols and two Smith & Wesson revolvers.
However, the police firearms-licensing office was unaware that complaints had been made about Hamilton's behavior towards young boys at after-school clubs that he ran.
The Snowdrop Campaign successfully argued for deeper background checks of firearm certificate applicants.
Only weeks after Dunblane's 1996 tragedy, a similar mass shooting shook Australia when 35 people were killed at the site of a historic penal colony at Port Arthur, Tasmania.
The shooter, who was later assessed to have the IQ of an 11-year-old, told investigators that he'd paid cash for firearms at a local gun dealer.
Among the young children who escaped from Dunblane Primary School was Andy Murray, now 28 and a British tennis champion. His mother, Judy, revealed she had once given a ride to the shooter, who was involved in local boys' after-school clubs.