What metrics will we use to define whether or not a certain endeavor is achieving its goal? And if we’re not achieving that goal, how will we know? What changes will we make? How will we test those changes?

These are the questions regularly asked when designing systems and software. Metrics focus energies on high-leverage efforts while eliminating distraction.

A decade ago, an act of terrorism killed thousands of Americans. Our nation’s collective outrage and disgust led us into two trillion-dollar wars. Unfortunately, our nation’s lack of clarity surrounding our measurement for success has led many to question our efforts. If our metric was simply to eliminate acts of foreign terrorism on American soil, then I guess we’ve done okay. The same could be said if the metric was the number of key terrorist leaders killed. Regardless, the cost and impact on American society over the last decade has been steep, leading many to confusion and disillusionment.

In this same decade over 100,000 Americans have been murdered with a gun by other Americans. This figure does not include suicides or accidental shootings (in which case the number would be much higher).

This is staggering. And unlike the tragic events of 9/11, these are crimes we have committed against ourself.

If the deaths of thousands at the hands of foreign terrorists gave us the resolve to wage wars halfway around the world, what must it take for us to examine ourselves?

In the Sermon on the Mount, Jesus tells his followers to remove the log in their own eye before they reach for the spec of dust in someone else’s.

America, we have a log in our eye.

Over 100,000 of our brothers and sisters, parents and children are dead because of our refusal to aggressively set a goal and measure against it. I’m as guilty of this as anyone.

Over 30 Americans will die today due to gun violence. Individually, we rarely register these “one-off” type events. It takes something higher profile — like a mass shooting — to grab headlines. Even then, shootings at a theater in July and a Sikh temple in August (along with at least eight other mass shootings this year) have done little to spur us to act.

I sat by and watched it happen too.

Three days ago our nation was stunned by yet another mass shooting. This time the victims were 6- and 7-year-olds. Twenty of them.

This one sank in hard — much like the Columbine shooting in 1999. At the time I was just a few years older than the students who were killed. Today I’m a father. My oldest is six, the same age as many of the victims. I can no longer sit idly while expecting others to take up the call.

To help us act, it’s time we all call a spade a spade. Guns kill.

This is their intended purpose. They are an invention of war. Even when the personal intention of ownership is self-defense, a gun’s purpose is still to kill. Sure, guns have other uses as well — some practical, some recreational — but their scope is well defined. Even hunting, let’s be real, is killing. This is not intended as a guilt trip, rather an exercise in definition. Personally I have no problem with hunting. I grew up in Texas and New Mexico, and I will accept that there remain valid reasons to own a gun in America. Self-defense may even be one of them.

But if we aim to set goals, we must be crystal clear with our definitions. Whether taking the lives of animal or people, a guns kill. And in tens of thousands of instances each year, it happens that guns kill people. We must be honest as we continue this discussion. Rhetoric will not help us.

Since the U.S. Fish & Wildlife Service continues to note the decline in hunters across America (about 5 percent of Americans hunt each year), we can assume most guns are purchased with other uses in mind — whether recreation, self-defense or simply collections.

And purchase them we do. We love guns in America. LOVE them. A Gallup survey from 2011 says 47 percent of American households own a gun. A CNN article from earlier this year cites a lower household percentage, but notes that the households that own guns own several. As a nation we own almost as many guns as we own cell phones.

Think about that.

Now let’s imagine for a moment that after the Columbine shooting in 1999 we sat down and agreed, as a nation, that we should dramatically reduce the number of gun-related homicides while eliminating mass shootings all together. This seems like a reasonable goal we could all agree upon.

Let’s also imagine our hypothesis as a nation was that by increasing the availability of handguns through concealed-carry permits that we would deter and defend ourselves from the threat of other Americans with guns.

It actually turns out we don’t need to imagine too hard; this is effectively what we decided to do. Here’s an animation illustrating the growing availability of concealed carry permits starting in 1986. You’ll notice a large increase of States legalizing concealed weapons around 1996 and another wave around 2003.

Now, once again, if our goal was dramatically fewer homicides and no mass shootings after Columbine — and our method for accomplishing this goal was to increase the legal availability of guns (and increase, we have) — our results are not acceptable.

Gun Rights advocates will point out that homicide rates are down since the mid-90's when many states began to make concealed carry licenses popular, and they’re correct. But the rates are still nowhere close to where they should be. We’re simple back to where we were a few decades ago before gun violence skyrocketed in the 80's. And we haven’t slowed mass shootings at all. We can do better.

Many will point out, of course, that there are often several ways to move a metric. No doubt there will be renewed calls to our treatment for the mentally ill. And we should. Helping the mentally ill is not likely to be the divisive issue here. Neither will it be the most impactful. When 47 percent of American households own a firearm, the odds of an individual with mental health problems obtaining possession of a gun are startlingly high. Put simply, when examining this venn at a glance, it will likely be easier for us to identify the guns than the mentally ill.

Sadly, we are are more passionate in defending our obsession with guns than we are eliminating gun violence in America.

If we wish to truly change this reality we will set big goals, like reducing the number of gun-related homicides in America by 50% in 10 years. And by eliminating mass shootings altogether. If this sounds crazy, you’re not thinking big enough.

Achieving these goals will require both public and private action. Our leaders and lawmakers must immediately rethink the status quo as it’s becoming painfully clear our current ideology on the subject is a failure.

A real ban on ridiculous “assault” type weapons is a no-brainer. While these are only responsible for a small percentage of firearm deaths, their role in mass shootings is unquestionable. There is no true need for these in society and the culture they promote is not something we as Americans should aspire to.

With 310 million firearms currently in America’s private arsenal, we may be forced to consider more visibly present security at places like schools, churches, malls and sporting events until we curb our gun addiction. That we are forced to consider this is pathetic and we should own up to this responsibility.

Of course, stricter controls, sale limitations, registration, and tracking of handguns — to keep guns out of the hands of people who have absolutely no reason owning one — will bring more significant gains.

At first blush, we don’t want to hear this because we like our “freedoms” and “rights.” It’s easier to simply hold up the Second Amendment as our blind rationale without considering the context or spirit under which it was drafted. Changing the mindset of our nation on this front will not be popular, and navigating it at a political level will be difficult.

This is where the private sector comes in to play. First, we must hold our leaders feet to the fire on both sides of the aisle. Action is needed. Now.

Second, you and I need a gut check. This is far more impactful than anything the government will do for us. Do we really need all of these weapons? Of course, the answer is no. And we don’t need to wait on the government to change laws in order for us to have a change of heart.

Just ask a handful of residents in Brooklyn who, over the weekend, voluntarily turned in over 134 firearms to law enforcement officials as part of a buyback program sponsored by the Brooklyn police department. A grandfather brought in a revolver found in a young grandson’s drawer.

Finally, we must measure. Set audacious goals, change our behaviors, change our laws, then measure ruthlessly. It’s the only way we’ll know if our actions are leading us to results.

Measure in six months. How did we do? Are the numbers related to gun violence trending downward? Are they trending downward at a rate fast enough to get us to 50% fewer gun-related homicides in a decade?

Measure again in a year. Are the numbers holding up? If so, are their ways to accelerate the trend? If not, is a change in methodology needed? Is a change in politics needed? Elections are being won with big data now. Don’t tell me we can’t do the same to eliminate gun violence.

Our calls for action must be coupled with measurement and accountability. We must understand definitively what is working and what doesn’t. And we must be willing to act and react in accordance those results without prejudice — even if it requires sacrifice on our part. As individuals and as a nation.

Let us not tell our children in ten years that we did nothing to stop this madness. The children of Sandy Hook deserve better. Our nation deserves better.