(AFP/Karen Bleier)

This post has been updated.

Thursday's deadly mass shooting in Oregon revived the all-too-familiar debate about the prevalence of gun violence in the United States, and what should or could be done to prevent future tragedies.

Amid that conversation came a call, once again, from academics who argue we should think of gun violence as a public health crisis. U.S. Surgeon General Vivek Murthy has referred to the problem as a health epidemic. President Obama on Thursday lamented "a Congress that explicitly blocks us from even collecting data on how we could potentially reduce gun deaths."

[Another day, another massacre — and it’s hard to explain why]

We spoke on Friday with Daniel Webster, who directs the Johns Hopkins Center for Gun Policy and Research in Baltimore, about his view that gun violence is best viewed as an urgent public health problem, one deserving of as much scrutiny and research as any infectious disease. His answers have been edited lightly for length and clarity:

WP: Why is gun violence a public health issue? How should people think about that?

Webster: If you simply look at the number of deaths, the number of people wounded, the number of people are affected through trauma, it touches a lot of people. If affects the basic things we track in public health … Like so many public health problems, you may have some communities or individuals with very low risk, but some communities where it truly is the most important public health problem that they have to deal with.

Oregon lawmakers and officials call for conversations on gun violence and gun control, saying it's time to prevent the continuation of U.S. mass shootings. (Reuters)

What explains the difference of two or more decades [of life expectancy] between a male who lives in West Baltimore, in a disadvantaged area, versus Roland Park in the northwest part of Baltimore, a really affluent area? Well, there’s probably a number of things. But one of the biggest things that we find is risk of dying by gunshot. It just affects the basic things we care about in public health – the mortality, the life expectancy, morbidity, mental health. It affects all of those things in pretty profound ways.

More importantly, what do you gain by looking at this from a public health lens? … It’s a much more practical, applied scientific field. We’re very solution focused. We’re trying to figure out how we can lower the mortality and morbidity from this problem. We draw upon what we’ve learned from other kinds of problems.

[Why the CDC still isn't researching gun violence, despite the ban being lifted two years ago]

For instance, what have we learned from the dramatic success story of how we’ve reduced mortality from motor vehicle crashes? There are a number of things we did that are transferable to the problem of gun violence. Both of those problem affect young people. On the driving side, we raised standards for driving when you’re young; we could raise standards for owning a gun, particularly when you’re young. We learned that you could design cars to be safe. Well, we could do the same with guns and save some lives…That’s where I think the real value is, is that it opens you to having a fuller understanding of the problem and what you can do to solve it.

WP: In a nutshell, what would you tell people about the data we don’t have that we should have? What research don’t we have that perhaps we should?

Webster: Some of the most important data we lack is what impact different gun laws have. There’s some research on that, but it’s actually pretty sparse and has important limitations. If we had a disease that was killing as many people as our guns in our country, we would devote a lot more resources to make sure we had the best data, the best research to know what is most affected.

We’ve really only scratched the surface, in my opinion. This is something I’ve been working on for most of my career. It’s not like we know nothing, but there are a lot of basic things we don’t know … Background checks, for example. The proposals [in Congress] and new laws that have been passed [in several states] that extend background check requirements for private gun sales -- we don't know enough about how well those work.

I've completed and published some recent studies of the effects of that policy when it's implemented through a handgun purchaser licensing system, and I think we have pretty compelling data to suggest that's a policy that reduces gun homicides and suicides. But the more common ways that background checks are being proposed or implemented, we really don't know yet what the impact of those laws are. They haven’t been thoroughly studied. Even fundamental questions of whether you are safer carrying a gun around with you or not has not been answered adequately.

I’m sure I could go on.

WP: What is the main obstacle of learning what we need to learn, of getting the research done?

Webster: Funding would be the number one thing. Secondly, sometimes in order to do that research, you need not only the actual funds, but buy-in and cooperation from people like law enforcement agencies. Sometimes you get that, and sometimes you don’t.

[White men are at higher risk of suicide]

On the whole policing side of things, the places where gun violence is the greatest – one such place is where I work, in Baltimore – they are the most taxed for resources because they are fighting so much violent crime. Yet, they stand the greatest benefit to actually having better data about that problem and what to do about it. But I’ve struggled over the 24 or 25 years I’ve worked in Baltimore to have that agency actually cooperate and really follow through and be helpful in some instances. Not because they don’t like research or they don’t like me, but because it costs them resources, too.

Congress definitely stands in the way of federal funding [for gun violence research]. They control the purse strings. They could change this today, if they wanted to. They’ve blocked what the CDC can do on this. The National Institute of Justice, the research branch of the [Department of Justice], over the years has funded some kind of research relevant to gun violence, but it’s really been a drop in the bucket … You still have to answer these fundamental questions that have an enormous impact on public safety.

WP: Do you see anything in this latest mass shooting in Oregon changing anything in a way that helps researchers study the public health aspects of gun violence?

Webster: I’m reluctant to say. I don’t know enough about this young man and all the circumstances yet. I do want to point out what is perhaps obvious: Even though we’ve had a noteworthy increase in mass shootings in recent years, they still represent a relatively small proportion of overall gun deaths. It’s a bit frustrating, as a researcher, that the public only thinks about this and gets information about this when they are poring over the particulars of a mass shooting.

[Those who murder strangers versus domestic killers]

That has really made it difficult for us to have broader advancements on this problem. Because if you say “gun violence” to an average person, they’ll think, “Oh, mass shootings in movie theaters or college campuses or elementary schools.” And while it’s horrible that we even have to think about those kind of events, the solutions we come up with to address mass shootings are very different, sometimes, than what happens in Baltimore every day.

WP: And you’re saying the latter is the biggest piece of the public health problem?

Webster: Absolutely. And, arguably, something you can have a better impact on. The more rare something is, the less predictable it is. The less predictable it is, the more difficult it is to prevent it. But I can zero in on a map of West Baltimore, and it’s pretty easy to predict that within a week, someone is going to get shot there, you know? So let’s zero in on what you can do to prevent that.

But where’s the next mass shooting going to be? Do you know? Do I know? Nobody knows.

[9 ways to improve your mental health]