By Seth Williams

In Newtown, Conn., last week, 20 children kissed their parents goodbye and headed off to a day in the first grade. They were excited. It was almost the weekend. It was almost winter break. One would never imagine that they were saying goodbye to their parents for the last time.

In Philadelphia, there are hundreds of families forever broken by the loss of children to gun violence. Each year, more than 300 mothers in our city join the ranks of the bereaved. I see it happen in real time as the cold facts flash across my BlackBerry; "black male 18, gunshot wound to head, dead on arrival. ... " The violence is so frequent that we have become numb to it. We just keep adding candles, teddy bears, and balloons to street-corner memorials.

As President Obama said in Newtown, "Are we to accept that there is nothing we can do? Are we afraid to even try?" As an American, a father, and as the district attorney for a city cursed by epidemic levels of gun violence, I am not afraid, and I am going to try.

Let's start by putting everything on the table without regard to political constraints - without giving up before we even begin. By everything, I mean every idea. The Jesuits at Georgetown University taught me that everything should be questioned. Let us evaluate ideas based not on whether they offend the left or the right, but on whether they actually have a chance of working. Here are a few:

Ban assault weapons and large-capacity clips. A high volume of fire increases the likelihood that stray bullets will hit bystanders. And no one needs all that firepower for any lawful purpose.

Eliminate the loophole that makes it a mere misdemeanor for someone to carry illegal guns when his prior convictions were for juvenile crimes.

Create mandatory prison sentences for possessing illegal firearms in Philadelphia. It has worked in New York and other cities. Let's try it here.

Modernize standards for involuntary commitment and ensure adequate treatment of serious mental illness.

These are some basic, commonsense proposals, but I know there are others. If you have an idea and believe it will work, please let me know.

We can do better. We must.