 People are getting shot all around me. Hundreds of students ran for their lives. We didn't think this would ever happen. The shooting at an elementary school in Newtown, Virginia Tech, Parkland, Columbine High School, a total of 15 people, 33 dead, 20 children, 7 adults. More than 240,000 US students have experienced gun violence at school since Columbine in 1999. But in the UK, it's a different story. Private ownership of all handguns and semi-automatic rifles is banned, a concept unimaginable in America. But how have these two inextricably linked nations ended up with such vastly different attitudes on guns? And how did this massive change in the UK even happen? To understand, we have to go back to 1996, when the Dunblane Massacre changed everything. Brief, sharp and disbelief in the Scottish town of Dunblane. A former scout leader with a grudge. It is a tragedy without precedent. 16 tiny children died right here at Dunblane Primary School. The massacre, carried out by a man who had licences for his guns, was enough to change the UK's gun laws forever. What's truly amazing is that by the end of the next year, it became illegal to own a handgun in the UK. But how did the UK get to that point so fast? It was mainly due to the activism from those personally affected by the attack. My daughter Sophie was one of the 16 young children who were shot dead at Dunblane Primary School. She and I were on our own. She was my only child. Dr Mick North was an academic before the shooting, but after, he found it impossible to return to that life. So he devoted himself to making sure other parents never had to experience his agony by becoming a gun control activist. Hi. One of my initial reactions after Dunblane was a feeling that this should never have happened because the guns that the perpetrator used have been too easy to come by. Dr North combined forces with other people who were touched by Dunblane, like former Scottish Labour MP Richard Simpson. Now he was a doctor at the local hospital at the time, but then after that experience, he changed his entire career, became a Labour MP and helped to lead the motion to change the gun laws in the UK. What I discovered was that the then Conservative government was in the process of actually seeking to deregulate the process by which guns were regulated in the United Kingdom, and that really made me very annoyed. These two men were part of a movement fighting to be heard by politicians. Residents of Dunblane and relatives of victims started speaking out and organising public relations campaigns and creating petitions. Politicians weren't necessarily used to hearing from the victims of shooting incidents. Everyone who says, I enjoy the sport, I want to hold the gun in my hand and have the live ammunition. What I say is, you have those emotions for enjoying your sport, but feel the emotions of a parent who is never going to see their child again. There was a really massive groundswell of it like the climate extension movement now. It wasn't highly coordinated or paid for. So we had a petition called the Snow Drop Petition which was getting the public to sign up for a ban on handguns, eventually gaining over 700,000 signatures. Within two years, a total ban on handguns had been introduced in this country. By 1999, over 165,000 guns and over 700 tonnes of ammo had been surrendered. There was a lot of opposition to it and it was suggested that it would actually badly affect people who use guns for sport, but it hasn't done so. What we did was a major achievement and I'm very satisfied with what we were able to do. Dunblane happened, the gun laws were overhauled. Before Columbine even happened two years earlier, it was like the precedent was set. We knew what was starting to happen across the world. And two years later, on April 20th 1999, two teenagers shot and killed 12 fellow students and a teacher at Columbine High School near Denver, Colorado. Just like Dunblane did in the UK, Columbine shocked Americans. It wasn't the first school shooting in the US, but those images captured on live TV set something off that had ripple effects throughout the country. Like in Dunblane, no one was closer to the situation than the victim's parents. I'm the father of Daniel Mauser. He was one of the students killed at Columbine High School. He was 15 years old. Like McNorth before him, Tom devoted his life to fighting for gun control, even taking a year off from work to lobby at the state capitol. Just two weeks before Columbine, at the dinner table, Daniel asked me a question based on something a conversation he had with other members of the debate team. He said, Dad, did you know there were loopholes in the Brady Bill? The Brady Bill is a national law that requires background checks to purchase a gun. And I just kind of blew it off. He was then killed with a gun that was purchased through a loophole in the Brady Bill. I mean, how could I not act on that? I mean, that was very prophetic. And it made me realize that when we have loopholes like that, but we have so much carnage in this country, we have to do something about it. I became very vocal, active. And Tom did make some very real progress on a state level soon after. Helping to introduce a bill to close the same gun show loophole he and Daniel had discussed over dinner. In 2000, the public voted and passed Colorado's answer to the Brady Bill by an overwhelming majority of about 70%. I felt that I did something to honor Daniel. I did something in response to something he brought up to me. But this small victory at the state level in Colorado was overshadowed by strong national backlash against gun safety laws. Barely a year after Columbine, then-NRA President Charlton Heston gave this famous threat. From my cold, dead hands. In America, we are so wrapped up in individualism and rights that we say, well, no, we can't do that because it might possibly affect my rights. And for a lot of people, that's more important than what could possibly happen to them or their neighbors. It's a cultural issue that is very starkly different between us and other nations. I think it's shameful in the U.S. that we have failed to really react in any significant way. Since Columbine, the narrative in the U.S. around gun rights and gun control has only become more polarizing. Restricting law-abiding Americans from acquiring guns is obviously unconstitution. Is it time to repeal the Second Amendment? The left has their rigid, radical, anti-gun agenda. Hell, yes, we're going to take your AR-15, your AK-47. In the U.S., barely any federal gun control laws have passed since Columbine. In fact, experts say the most significant change in gun law is when politicians let a Clinton-era assault weapons ban expire in 2004, making assault weapons like AR-15s legal again. Since then, the AR-15 has been used in almost every notable mass shooting in America. And the problem continues to get worse. The U.S. has more firearms per person than any other country in the world. And it's the only country in the world that has more guns than people. And the U.S. gun homicide rate is 25 times that of other high-income countries, including the U.K. The main problem is not necessarily the Second Amendment, but how that has been interpreted. In America, there needs to be an understanding of how to tighten the law without grossly infringing on what are perceived of as rights under the Second Amendment. But it does seem ridiculous to use the words of the founding fathers to decide how you control or don't control weapons that are usually used in war zones. There have been so many mass shootings since Columbine that many Americans feel hopeless about reform. The fact remains, however, that 61% of Americans do support stricter gun laws. And there are many potential changes, such as closing the gun show loophole or restricting assault weapons that would make a huge impact and would not go as far as a total ban on firearms. It takes a long time sometimes. It's not just changing the laws. You also have to change culture to be willing to change the laws. And perhaps there'll come a time when enough people vote in politicians who will be supportive of the gun control measures that America needs and deserves. No one has kids so they can buy them bulletproof backpacks. You have kids so that they can hopefully thrive in a better world than you did. We really have to ask ourselves if we're giving them that opportunity.