Stephen Dubner

If you had to sum up David Riedman's central motivation, it might be this, protecting innocent people from terrible things.

Reidman runs the school shooting database out of his guest bedroom. He has recorded every school shooting in the U.S. since 1966, more than 3,000 incidents and 1,000 deaths.

Reidman runs the school shooting database out of his guest bedroom. He has recorded every school shooting in the U.S. since 1966, more than 3,000 incidents and 1,000 deaths.

Reidman runs the school shooting database out of his guest bedroom. He has recorded every school shooting in the U.S. since 1966, more than 3,000 incidents and 1,000 deaths.

Why does Riedman care about all these details? This goes back to what Ed Gallia, the astrophysicist turned disaster scholar, told us. That most tragedies come at the end of a chain of events. For David Riedman, assembling that chain takes a lot of time.

Why does Riedman care about all these details? This goes back to what Ed Gallia, the astrophysicist turned disaster scholar, told us. That most tragedies come at the end of a chain of events. For David Riedman, assembling that chain takes a lot of time.

Why does Riedman care about all these details? This goes back to what Ed Gallia, the astrophysicist turned disaster scholar, told us. That most tragedies come at the end of a chain of events. For David Riedman, assembling that chain takes a lot of time.

David, you sent us an email a while back. That sounds to me like both an empirical argument and almost a philosophical argument. Can you unpack that for me? What do you mean by that?

David, you sent us an email a while back. That sounds to me like both an empirical argument and almost a philosophical argument. Can you unpack that for me? What do you mean by that?

David, you sent us an email a while back. That sounds to me like both an empirical argument and almost a philosophical argument. Can you unpack that for me? What do you mean by that?

At this point, it was still not known that he was in possession of the gun?

At this point, it was still not known that he was in possession of the gun?

At this point, it was still not known that he was in possession of the gun?

The shooter is serving a life sentence. And last year, his parents were both convicted of involuntary manslaughter and sentenced to 10 to 15 years in prison. The first parents in the U.S. to face criminal charges for a school shooting committed by their child. Several lawsuits against the school district were dismissed.

The shooter is serving a life sentence. And last year, his parents were both convicted of involuntary manslaughter and sentenced to 10 to 15 years in prison. The first parents in the U.S. to face criminal charges for a school shooting committed by their child. Several lawsuits against the school district were dismissed.

The shooter is serving a life sentence. And last year, his parents were both convicted of involuntary manslaughter and sentenced to 10 to 15 years in prison. The first parents in the U.S. to face criminal charges for a school shooting committed by their child. Several lawsuits against the school district were dismissed.

David Riedman thinks that school officials may have made mistakes that day, but he says... If you take the chain of events approach, there is a much bigger problem that leads to a failure like this.

David Riedman thinks that school officials may have made mistakes that day, but he says... If you take the chain of events approach, there is a much bigger problem that leads to a failure like this.

David Riedman thinks that school officials may have made mistakes that day, but he says... If you take the chain of events approach, there is a much bigger problem that leads to a failure like this.

So let me ask a few questions about that. What's your generic or descriptive term for what you are seeking here, what you're advocating? Is it like a red flag system for school shootings?