Of course, most of the mass killings we read about in America involve a gun - they’re so easy to get. And so if the gun laws were tighter and there were fewer guns people would find it harder to shoot up a school or a church.

But the chances are that not being able to get their hands on a gun wouldn’t stop them killing - it would just force them to find a different weapon. Because the fact is that most mass killers don’t kill because they happen to stumble across a gun - they kill for some other reason.

So let’s take a look at what some of those reasons could be…

Hatred

Emotions can make us do some strange things and hate is one of the strongest emotions there is - it can certainly cloud our judgement. And if hatred and resentment build up over a long time, it can make people snap.

For example, when British taxi driver Derrick Bird killed 12 people and injured 11 others in Cumbria in 2010, before turning his gun on himself. He’s suspected of acting out of hatred for his former employer, the Sellafield nuclear power plant, as he was fired from his job after being accused of stealing. Three of the people he killed used to work at the power plant.

Hate also played a part in Omar Mateen’s killing spree, when he shot 53 people in a gay nightclub in Florida in 2016. His father told police that just before the attack Omar had seen two men kissing in the street and got really angry. Interestingly, his hatred of homosexuality might also have been partly self-hatred - it’s since been discovered that he’d actually visited the gay nightclub several times before and that he’d downloaded a number of gay apps to his phone. So it’s possible that Omar was struggling with his own sexuality and that was all mixed up with his hatred of gay people.

Mental illness

Various psychotic illnesses, such as schizophrenia or severe bi-polar disorder, are often associated with mass killers. This is because they can result in people disconnecting from reality - experiencing delusions and hallucinations like hearing voices or seeing things that aren’t really there.

Not everyone with these issues will become a mass killer, of course. But they provide the right kind of mental conditions for someone to underestimate the seriousness of their actions, or even to think that what they’re doing is a reasonable and right way to behave.

With these kinds of mental health issues, getting help is vital - but finding the right treatment isn’t always easy and in the US particularly it can be quite expensive. Which could mean that people with serious psychological problems end up acting out and harming others because they’ve not been given the proper care.

Manliness

Men are responsible for 85% of all murders. But why is that? Why aren’t there more murderous women? Well, it seems to come down to two things - hormones and culture.

Firstly, hormones - testosterone is a hormone that men have loads more of than women, and it tends to make people aggressive. So both men and women might experience mental health issues or struggle with hatred, but only men have a body pumped full of hormones that are more likely to make them do something violent.

Then you combine that with culture - in the West we often send boys the message that to be a ‘real man’ you must be tough, confident and unemotional. So if a boy struggles to fit into that macho mould, they’ll probably feel disappointed and humiliated. And when resentment builds up, it’s not uncommon for them to resort to violence as a way of dealing with their frustration and embarrassment.

The killer or the trigger?

If someone is feeling lonely, angry, or mentally confused enough that they think lashing out at people in a deadly way is their best option, taking their gun away probably isn’t going to stop them. In the last decade, the world has experienced mass killers who’ve used bombs, driven lorries into crowds, crashed planes into buildings, stabbed people and shot at people with a bow and arrow.

But it’s also true that guns make it easier to kill more people in a shorter period of time, so the damage they do compared to some of those other methods is likely to be higher. So taking someone’s gun away might not stop them killing people, but it could at least stop them killing so many.

Ultimately there are all kinds of reasons why guns might be bad - but are you going to put ‘because they’re responsible for mass killings’ on your list, or leave it off? In a mass shooting where does the blame lie - with the gun or with the person holding it? That’s up to you.