This is Fresh Air.

I'm Dave Davies and today for Terry Gross.

There are a few events in the news that are so emotionally powerful that years later,

you can still remember where you were when you first heard about them.

For most of us, the Sandy Hook School's shooting is on that list.

Our guest journalist Mark Fulman has been studying mass shootings for much of the past decade,

and he's led a team that assembled a database of more than 120 of them that have occurred

over the past 40 years.

His new book is about efforts underway to stop such tragedies before they occur, by studying

the psychology and behavior of mass shooters, looking for those patterns at schools and

workplaces, and intervening to get trouble to people help before they turn to violence.

It's an emerging field called Behavioral Threat Assessment, and it's now mandated for

schools in some states.

Mark Fulman is a longtime journalist and national affairs editor for Mother Jones.

His writing and commentary have appeared in the New York Times and the Atlantic.

His new book is Trigger Points, Inside the Mission to Stop Mass Shootings in America.

Well, Mark Fulman, welcome to Fresh Air.

Thanks so much, Dave.

It's great to be here.

You know, when you talk about mass shootings and doing something about it, the first thing

people usually think of is gun regulation and background checks.

That's not your focus here.

...